Are you building a custom app?
If so, you will need an external method of handling payments and verifying payments, per this page.
Please do not facilitate financial transactions on the Airtable platform. You are welcome to independently monetize your app through your own channels and have users validate using an API key. You can refer to the Formstack Documents app or Jira Cloud app as examples.
Your app can have a link to your website where you handle the financial transaction and provide the user with an API key or similar credentials. Then have your app verify the API key.