How do I connect my currently existing code to my Supabase database?

supabase.auth.getUser(authToken).then(({data, error}) => {
        if (error || !data.user) {
            console.log(`Got error ${error?.message}`);
            return res.sendStatus(401);
        }
        let id: string = data.user.id;
        let user = users.get(id);
        if (!user) {
            user = new User(id);
            users.set(id, user);
        }