Resolve the x402 scheme for a plan by fetching plan metadata (cached). Used in callsites that don't have a token to extract scheme from (402 responses and token generation).
The Payments instance for API access
The plan identifier
Optional
Optional explicit override; returned immediately if provided
The resolved scheme type
Resolve the x402 scheme for a plan by fetching plan metadata (cached). Used in callsites that don't have a token to extract scheme from (402 responses and token generation).