My experience on MacOS with Homebrew has been that pinentry-mac needs to be configured. There's no TTY in the IntelliJ git console and you don't get errors about pinentry, just the above errors about gpg failing.
❯ cat $HOME/.gnupg/gpg-agent.conf
pinentry-program /opt/homebrew/bin/pinentry-mac
allow-loopback-pinentry
❯ pinentry-mac
OK Pleased to meet you
^C
The default gpgconf
seems fine.
❯ gpgconf
gpg:OpenPGP:/opt/homebrew/Cellar/gnupg/2.4.3/bin/gpg
gpgsm:S/MIME:/opt/homebrew/Cellar/gnupg/2.4.3/bin/gpgsm
keyboxd:Public Keys:/opt/homebrew/Cellar/gnupg/2.4.3/libexec/keyboxd
gpg-agent:Private Keys:/opt/homebrew/Cellar/gnupg/2.4.3/bin/gpg-agent
scdaemon:Smartcards:/opt/homebrew/Cellar/gnupg/2.4.3/libexec/scdaemon
dirmngr:Network:/opt/homebrew/Cellar/gnupg/2.4.3/bin/dirmngr
pinentry:Passphrase Entry:/opt/homebrew/opt/pinentry/bin/pinentry
gpg-agent
will automatically be started as required. Then pinentry-mac can be configured to use the Keychain Access.
❯ ps x | grep gpg-agent
10867 0:00.17 gpg-agent --homedir .../.gnupg --use-standard-socket --daemon
❯ gpg-agent
gpg-agent[10869]: gpg-agent running and available