The process depends on who processed your payment.
App Store: Open Apple’s Report a Problem service, sign in with the purchasing account and choose Request a refund. Select the reason and purchase, then submit. Apple refund guidance
Google Play: Use Google Play’s refund request process with the purchasing Google Account. Follow any instructions to contact the developer if needed.
Website: Follow the Chatbot website refund guidance or contact support with your order details.
Approval depends on the purchase and applicable policy. If you also want to prevent another renewal, cancel it separately through the billing provider.