Need to setup gpg-agent first, on OSX I use keychain (it also does ssh-agent)
$ brew info keychain
keychain: stable 2.8.5
User-friendly front-end to ssh-agent(1)
https://www.funtoo.org/Keychain
/usr/local/Cellar/keychain/2.8.5 (7 files, 108.5KB) *Last updated March 28, 2021
There are now two ways to approach this:
This Gist explains how to do this using gpg in a step-by-step fashion. Kryptonite is actually wickedly easy to use-but you will still need to follow the instructions