How to cast a Clerk userId to a MongoDB ObjectId

Question

In the following code, is there a way to cast the clerk userId to an ObjectId? In this cased, clerkId is user_2eImnitE0bBq3mk06dsyh6u3sey and I need it to be something like 65d7b4e1b10459878c61cc6b.

This is because apparently sessionClaims in Clerk doesn't have userId on it, just user_sub, so this returns me null and I need to compare the Clerk userId on the database. Any help, please?

import EventForm from "@/components/shared/EventForm";
import { auth } from "@clerk/nextjs";

const CreateEvent = () => {
  const { userId } = auth();

  //original code
  const { sessionClaims } = auth();
  const userID = sessionClaims?.userId as string;

  return (
    <>
      <section className="bg-primary-50 bg-dotted-pattern bg-cover bg-center py-5 md:py-10">
        <h3 className="wrapper h3-bold text-center sm:text-left">
          Create Event
        </h3>
      </section>

      <div className="wrapper my-8">
        {/* original code */}
        <EventForm userId={userID} type="Create" />
        <EventForm userId={userId as string} type="Create" />
      </div>
    </>
  );
};

export default CreateEvent;