execute postgres function without transaction isolation level

[0814celsus]

We have implemented a postgres role switching function which uses pg_audit/set_user and plpython3 for verifying and read out the role from a jwt token and the sets the role for the pg session according the defined role in the token. But this just work in a global not local scope. My question, is there a possibility to Execute such a function from duckdb to switch user role from an attached pg connection?