This usually means Slow Time Club hasn't picked up your purchase yet. The steps below fix it in almost every case.
Try these in order
Leave Slow Time Club and come back. Go to your Home Screen, wait a few seconds, then open Slow Time Club again. It checks your purchases each time you return.
Tap Restore on the plans screen. This asks Apple for everything you've bought with your Apple ID.
Check your Apple ID. Go to Settings → your name → Media & Purchases and make sure it's the Apple ID you paid with. A purchase only shows up on the Apple ID that paid.
Check the payment went through. Go to Settings → your name → Subscriptions. If Slow Time Club isn't listed, Apple may not have finished the payment. Look for a receipt email from Apple.
Restart your iPhone, then open Slow Time Club and tap Restore again.
Waiting for approval?
If a family organiser needs to approve the purchase with Ask to Buy, or your payment method takes a while to confirm, your subscription turns on once Apple confirms it. Open Slow Time Club again after you see Apple's confirmation.
Please don't pay a second time while you wait. If you think you've been charged twice, request a refund for the extra charge at reportaproblem.apple.com.
Still stuck? Email us at [email protected] with the email address on your App Store receipt and roughly when you bought. You don't need to get past the plans screen to reach us.