supabase.auth.session() Error

Use to be using this function;

const isSignedIn = () => supabase.auth.session()? supabase.auth.session() : false;

const isSignedIn = () => supabase.auth.session()? supabase.auth.session() : false;

I'm getting;

Uncaught TypeError: supabase.auth.session is not a function

Uncaught TypeError: supabase.auth.session is not a function

It used to works few weeks ago! Has the function been changed?