You may no longer see the free Meetup “Starter” plan if you no longer qualify for it. In fact, the Starter organizer plan is reserved only for first-time organizers who have never had a paid organizer subscription. If you started another subscription or upgraded to a paid plan in the meantime, you'll no longer be offered to start a Starter subscription.
You can always check your account status by logging into Meetup and visiting Account Settings → Organizer Subscription. There, you can review whether you currently hold or have held a paid plan.
If you previously upgraded from the free plan to a paid one, you cannot revert to the free Starter plan under the current policy.
If you’ve never had a paid subscription and still don’t see the Starter plan option, contact Meetup support to verify whether it’s available in your region or if any changes have been made to eligibility.