From Oticons website

If the second letter in the serial number is an “A”, then it will work with the ConnectLine App for iPhone, iPad and iPod touch. If there is not a serial number on the bottom of the Streamer, that probably means that the streamer is an earlier version and will not work with iPhone, iPad or iPod touch.

The serial number is found on the bottom of your streamer. If you dont have a serial number your streamer will not work with connectline.

Need the right streamer about Oticon ConnectLine