Issues the migration code that lets the account move its Peppol participant identifier from B2Brouter to another provider. Hand the code to the gaining provider: they use it to claim the identifier.

The account must have a peppol transport whose identifier B2Brouter publishes; otherwise there is nothing to migrate and the request is rejected with a 409.

The call is idempotent: while a code is outstanding, every call returns that same code. To replace it, cancel it with DELETE and request a new one. Cancelling and re-issuing invalidates the previous code, so any copy already sent to the gaining provider stops working.

Issuing a code does not move the identifier and does not change reception: documents keep arriving at B2Brouter until the gaining provider completes the migration. Once a code has been issued and not cancelled, the peppol transport reports migration_pending: true; it stays true after the gaining provider completes the migration, and only turns back to false when the code is cancelled with DELETE.

The code is only returned by this endpoint and never appears in transport responses.