GPG

https://www.youtube.com/watch?v=AYegjnDWvww

install from source
https://pastebin.com/qPunEVxR fix the /r error with dos2unix command

Use latest autotools from GNU foundation such as make 2020 November, your linux distro most likely has the 2016 version resulting in compile errors for the needed packages.

links
https://unix.stackexchange.com/questions/60213/gpg-asks-for-password-even-with-passphrase/60439  auto encrypt decrypt https://stackoverflow.com/questions/30318041/gpg-decryption-failed-bad-session-key bad session key Encryption https://github.com/NicoHood/gpgit/blob/master/gpgit.sh