Purchase credits

Purchases credits for a Vercel team using the default payment method on file. The purchase is charged immediately via Stripe invoice. Supported credit types are v0, gateway, and agent. The amount field specifies the number of credits to purchase and must be a positive integer. An optional source query parameter can be provided to identify the caller. Defaults to api if not specified. This is only available for Owner, Member, Developer, Security, and Billing roles for the supplied team.