I was asked to send a scan of my ID and additional informaion to them.

In the end, I tried the suggestion of George Kyriakos again but used my first name a family name. I remembered that in Asia it is sometime the other way round and it seems, that in the Shangri-La Gold Circle system my first name is stored as my family name and though to give it a try.

Otherwise I would have simply sent them the requested information.