instrument_has_no_mandate
HTTP 409, type conflict_error.
That payment instrument cannot be billed on a schedule.
Why it happened
It carries no record of the payment that authorised it, which is what lets a card be charged again without the cardholder present.
How to fix it
Subscribe with a different card, saved from a checkout payment for this customer: a card saved when a checkout payment succeeds carries the record of that payment. Paying again with THIS card does not add the record today, because a card your account has already saved is reused as it is, with only its expiry updated. If you need this card on a schedule, contact support with the request id.
Retrying: retry only after fixing the instrument, to a different card saved from a checkout payment. This refusal happens while the request is processed, after its Idempotency-Key is claimed, so send the corrected request with a new Idempotency-Key.