Issues a new card directly for the specified customer. This is a convenience endpoint equivalent to POST /v1/cards with the customerId inferred from the path.
API key passed as a Bearer token. Format: ld_<env>_<prefix>_<secret> where <env> is test or live.
Unique key to ensure idempotent request processing. Reusing a key for a different route or method returns 409 Conflict.
"idk_a1b2c3d4-e5f6-7890-abcd-ef1234567890"
The customer ID (prefixed with cus_).
"cus_abc123"