This is confusing to me, because the point of the request seems to be “get a certificate”, not “get a self signed certificate generated by running the openssl command”. If you know how to get the result, it doesn’t really matter if you remembered offhand the shitty way or the overkill way.
Is it really more helpful to say “I remember how to do this, but let me lookup a different way that doesn’t use the tools I’m familiar with”?