According to https://pijul.org/manual/signing_patches.html to generate a secret key you need to type pijul keys --generate-signing but this is incorrect. The correct way is pijul key gen --signing. On top of that, if you don't specify a subcommand for key, it exits without printing anything.
pijul keys --generate-signing
pijul key gen --signing
This issue assumes that key has not been replaced to keys in newer versions (> 0.11.1).
Issue initially submitted by odiferousmint on GitHub.
There's a patch here but I guess pmeunier doesn't has much time now
I applied the relevant patches now, thanks!