Feature in auth0 to convert Auth0 Access token to custom token

Hi,

for accessing a postgresql database provided via cloud by supabase, i need to provide to them a custom JWT for enabling row-level-security for postgres. It looks like i need to use a cloud function at google or some other place to do the minting of the new JWT token with the content of the Auth0 token.

Now i wonder why this is not possible with Auth0 itself. Is this really not available because its really in the same domain space right? Something like Google Functions on steroids for exactly this purpose.

Or is there a different route that i missed so far? To provide more context. My environment is a SPA with Auth0 and i really dont want to have self maintained backend services.

Marc