What dialect should I use for r2dbc postgresql init.sql?

Question

The problem is: I need to create a function. If I call it in Idea Postgre console - it works If I add it to init.sql - it fails with $$ tag

create or replace function work(i integer) returns integer
language sql as
$$
select user_id from ttable;
$$

I need to know how to make r2dbc use the original syntax in init.sql