How do I add a new script arg to a pm2 process?

Once your process is already declared and running, you can check the arguments what were given on firing it up by running pm2 info <id>.

How do I update the script args that are shown on info? In my particular case, I'd like to add a new one to the existing set without having to delete and recreate the process.

EDIT I'm aware of this brief explanation on the official docs, but its phrasing is rather vague and it only provides examples of usage of --update-env with an ecosystem file, which I don't have nor I want to have.

via Nicolás Fantone