“Is there a substitute for “raspi-config” command?”
No that is an raspian program. There is some what a port in AUR but most things will not work on a 64bit program. This are done manually on an arch based distro. There will be a way to get it done but I am handicapped by not having a micrphone to test with. There are a lot of outdated guides out there and just have to find the right one. I was just now looking here:
Another thing I thought about is we have a setting in /boot/cmdline.txt that is not the default like raspian. We have it so one can select which monitor for the sound to be sent to but it does interfer sometimes with other devices. You might want to change this snd-bcm2835.enable_compat_alsa=0 to this snd-bcm2835.enable_compat_alsa=1 and reboot.