Somehow using Add/Remove Software App to build/install hplip-plugin it ended up with error and it aborted but using command line: sudo pacman build hplip-plugin it build successfully.
Now let see whether HP LaserJet 1020 will be recognised and Print.
[jfl@MNJROGTKPRO ~]$ pamac build hplip-plugin
Preparing...
Cloning hplip-plugin build files...
Checking hplip-plugin dependencies...
Resolving dependencies...
Checking inter-conflicts...
To build (1):
hplip-plugin 3.20.11-1 AUR
Edit build files : [e]
Apply transaction ? [e/y/N] y
Building hplip-plugin...
==> Making package: hplip-plugin 3.20.11-1 (Tue 05 Jan 2021 12:38:54 AM +08)
==> Checking runtime dependencies...
==> Checking buildtime dependencies...
==> Retrieving sources...
-> Found hplip-3.20.11-plugin.run
==> Validating source files with md5sums...
hplip-3.20.11-plugin.run ... Passed
==> Removing existing $srcdir/ directory...
==> Extracting sources...
==> Starting prepare()...
Creating directory /var/tmp/pamac-build-jfl/hplip-plugin/src/hplip-3.20.11-plugin
Verifying archive integrity... All good.
Uncompressing HPLIP 3.20.11 Plugin Self Extracting Archive..............................................................
==> Entering fakeroot environment...
==> Starting package()...
'/var/tmp/pamac-build-jfl/hplip-plugin/pkg/hplip-plugin/usr/share/hplip/scan/plugins/bb_soap.so' -> 'bb_soap-arm64.so'
'/var/tmp/pamac-build-jfl/hplip-plugin/pkg/hplip-plugin/usr/share/hplip/scan/plugins/bb_marvell.so' -> 'bb_marvell-arm64.so'
'/var/tmp/pamac-build-jfl/hplip-plugin/pkg/hplip-plugin/usr/share/hplip/scan/plugins/bb_soapht.so' -> 'bb_soapht-arm64.so'
'/var/tmp/pamac-build-jfl/hplip-plugin/pkg/hplip-plugin/usr/share/hplip/scan/plugins/bb_escl.so' -> 'bb_escl-arm64.so'
'/var/tmp/pamac-build-jfl/hplip-plugin/pkg/hplip-plugin/usr/share/hplip/prnt/plugins/lj.so' -> 'lj-arm64.so'
'/var/tmp/pamac-build-jfl/hplip-plugin/pkg/hplip-plugin/usr/share/hplip/prnt/plugins/hbpl1.so' -> 'hbpl1-arm64.so'
'/var/tmp/pamac-build-jfl/hplip-plugin/pkg/hplip-plugin/usr/share/hplip/fax/plugins/fax_marvell.so' -> 'fax_marvell-arm64.so'
==> Tidying install...
-> Removing libtool files...
-> Purging unwanted files...
-> Removing static library files...
-> Stripping unneeded symbols from binaries and libraries...
-> Compressing man and info pages...
==> Checking for packaging issues...
==> Creating package "hplip-plugin"...
-> Generating .PKGINFO file...
-> Generating .BUILDINFO file...
-> Generating .MTREE file...
-> Compressing package...
==> Leaving fakeroot environment.
==> Finished making: hplip-plugin 3.20.11-1 (Tue 05 Jan 2021 12:39:00 AM +08)
==> Cleaning up...
Checking keyring... [1/1]
Checking integrity... [1/1]
Loading packages files... [1/1]
Checking file conflicts... [1/1]
Warning: hplip-plugin: /usr/share/hplip/data/firmware/hp_laserjet_1000.fw.gz already existed in filesystem
It has been backed up to /usr/share/hplip/data/firmware/hp_laserjet_1000.fw.gz.old
Warning: hplip-plugin: /usr/share/hplip/data/firmware/hp_laserjet_1005_series.fw.gz already existed in filesystem
It has been backed up to /usr/share/hplip/data/firmware/hp_laserjet_1005_series.fw.gz.old
Warning: hplip-plugin: /usr/share/hplip/data/firmware/hp_laserjet_1018.fw.gz already existed in filesystem
It has been backed up to /usr/share/hplip/data/firmware/hp_laserjet_1018.fw.gz.old
Warning: hplip-plugin: /usr/share/hplip/data/firmware/hp_laserjet_1020.fw.gz already existed in filesystem
It has been backed up to /usr/share/hplip/data/firmware/hp_laserjet_1020.fw.gz.old
Warning: hplip-plugin: /usr/share/hplip/data/firmware/hp_laserjet_p1005.fw.gz already existed in filesystem
It has been backed up to /usr/share/hplip/data/firmware/hp_laserjet_p1005.fw.gz.old
Warning: hplip-plugin: /usr/share/hplip/data/firmware/hp_laserjet_p1006.fw.gz already existed in filesystem
It has been backed up to /usr/share/hplip/data/firmware/hp_laserjet_p1006.fw.gz.old
Warning: hplip-plugin: /usr/share/hplip/data/firmware/hp_laserjet_p1007.fw.gz already existed in filesystem
It has been backed up to /usr/share/hplip/data/firmware/hp_laserjet_p1007.fw.gz.old
Warning: hplip-plugin: /usr/share/hplip/data/firmware/hp_laserjet_p1008.fw.gz already existed in filesystem
It has been backed up to /usr/share/hplip/data/firmware/hp_laserjet_p1008.fw.gz.old
Warning: hplip-plugin: /usr/share/hplip/data/firmware/hp_laserjet_p1009.fw.gz already existed in filesystem
It has been backed up to /usr/share/hplip/data/firmware/hp_laserjet_p1009.fw.gz.old
Warning: hplip-plugin: /usr/share/hplip/data/firmware/hp_laserjet_p1505.fw.gz already existed in filesystem
It has been backed up to /usr/share/hplip/data/firmware/hp_laserjet_p1505.fw.gz.old
Warning: hplip-plugin: /usr/share/hplip/data/firmware/hp_laserjet_professional_p1102.fw.gz already existed in filesystem
It has been backed up to /usr/share/hplip/data/firmware/hp_laserjet_professional_p1102.fw.gz.old
Warning: hplip-plugin: /usr/share/hplip/data/firmware/hp_laserjet_professional_p1102w.fw.gz already existed in filesystem
It has been backed up to /usr/share/hplip/data/firmware/hp_laserjet_professional_p1102w.fw.gz.old
Warning: hplip-plugin: /usr/share/hplip/data/firmware/hp_laserjet_professional_p1566.fw.gz already existed in filesystem
It has been backed up to /usr/share/hplip/data/firmware/hp_laserjet_professional_p1566.fw.gz.old
Warning: hplip-plugin: /usr/share/hplip/fax/plugins/fax_marvell-arm64.so already existed in filesystem
It has been backed up to /usr/share/hplip/fax/plugins/fax_marvell-arm64.so.old
Warning: hplip-plugin: /usr/share/hplip/fax/plugins/fax_marvell.so already existed in filesystem
It has been backed up to /usr/share/hplip/fax/plugins/fax_marvell.so.old
Warning: hplip-plugin: /usr/share/hplip/plugin.spec already existed in filesystem
It has been backed up to /usr/share/hplip/plugin.spec.old
Warning: hplip-plugin: /usr/share/hplip/prnt/plugins/hbpl1-arm64.so already existed in filesystem
It has been backed up to /usr/share/hplip/prnt/plugins/hbpl1-arm64.so.old
Warning: hplip-plugin: /usr/share/hplip/prnt/plugins/hbpl1.so already existed in filesystem
It has been backed up to /usr/share/hplip/prnt/plugins/hbpl1.so.old
Warning: hplip-plugin: /usr/share/hplip/prnt/plugins/lj-arm64.so already existed in filesystem
It has been backed up to /usr/share/hplip/prnt/plugins/lj-arm64.so.old
Warning: hplip-plugin: /usr/share/hplip/prnt/plugins/lj.so already existed in filesystem
It has been backed up to /usr/share/hplip/prnt/plugins/lj.so.old
Warning: hplip-plugin: /usr/share/hplip/scan/plugins/bb_escl-arm64.so already existed in filesystem
It has been backed up to /usr/share/hplip/scan/plugins/bb_escl-arm64.so.old
Warning: hplip-plugin: /usr/share/hplip/scan/plugins/bb_escl.so already existed in filesystem
It has been backed up to /usr/share/hplip/scan/plugins/bb_escl.so.old
Warning: hplip-plugin: /usr/share/hplip/scan/plugins/bb_marvell-arm64.so already existed in filesystem
It has been backed up to /usr/share/hplip/scan/plugins/bb_marvell-arm64.so.old
Warning: hplip-plugin: /usr/share/hplip/scan/plugins/bb_marvell.so already existed in filesystem
It has been backed up to /usr/share/hplip/scan/plugins/bb_marvell.so.old
Warning: hplip-plugin: /usr/share/hplip/scan/plugins/bb_soap-arm64.so already existed in filesystem
It has been backed up to /usr/share/hplip/scan/plugins/bb_soap-arm64.so.old
Warning: hplip-plugin: /usr/share/hplip/scan/plugins/bb_soap.so already existed in filesystem
It has been backed up to /usr/share/hplip/scan/plugins/bb_soap.so.old
Warning: hplip-plugin: /usr/share/hplip/scan/plugins/bb_soapht-arm64.so already existed in filesystem
It has been backed up to /usr/share/hplip/scan/plugins/bb_soapht-arm64.so.old
Warning: hplip-plugin: /usr/share/hplip/scan/plugins/bb_soapht.so already existed in filesystem
It has been backed up to /usr/share/hplip/scan/plugins/bb_soapht.so.old
Checking keyring... [1/1]
Checking integrity... [1/1]
Loading packages files... [1/1]
Checking file conflicts... [1/1]
Checking available disk space... [1/1]
Installing hplip-plugin (3.20.11-1)... [1/1]
/var/lib/hp/hplip.state installed as /var/lib/hp/hplip.state.pacnew.
Transaction successfully finished.
[jfl@MNJROGTKPRO ~]$