I have seen the article: How-to verify GPG key of official .ISO images - Manjaro. However, that method doesn’t work for the i3wm version, at least. How can I verify the i3 minimal ISO image?
$ gpg --keyserver hkp://pool.sks-keyservers.net --search-keys 11C7F07E
gpg: data source: http://86.105.108.212:11371
(1) Philip Müller (Called Little) <philm@manjaro.org>
2048 bit RSA key CAA6A59611C7F07E, created: 2012-05-05
Keys 1-1 of 1 for "11C7F07E". Enter number(s), N)ext, or Q)uit > 1
gpg: key CAA6A59611C7F07E: public key "Philip Müller (Called Little) <philm@manjaro.org>" imported
gpg: Total number processed: 1
gpg: imported: 1
$ gpg --verify latest-minimal.sig manjaro-i3-20.2-minimal-201209-linux59.iso
gpg: Signature made 2020-12-09T22:40:10 CET
gpg: using RSA key 39F0EC1AE50B37E5F3196F09DAD3B211663CA268
gpg: Can't check signature: No public key