I'm trying to add a subscriber to a list by a SOAP call to the MC API, using this example:
The xml response return 200 OK and says that the subscriber was added to the list, but if I open the list then the subscriber doesn't shows. Also, if I execute the same call again then server responses with a 200 OK and says that the subscriber was already added.
I don't know if first I have to create the subscriber or that call create the subscriber and also add it to the list.
I was wondering if on the SOAP envelope I have to specify the id of the list or the external key.