getCallbackUrl

Returns the callback URL attached as the X-Callback-Url header for a given transaction-initiation operation, or an empty string to send no callback header for that operation.

operation is the endpoint's path segment — one of requesttopay, requesttowithdraw, deposit, refund, transfer, cashtransfer, invoice, payment, preapproval — allowing implementations to return a different callback URL per operation (or a single shared URL by ignoring the argument).

MTN posts the transaction result to this URL once the operation completes; the host must be registered/allowed for the API user. Defaults to an empty string (no callback) so the header is opt-in — implementations return a configured URL only when they want callbacks.

Parameters