can anyone tell me how to get the phone’s native phone number, thanks.
As far as I know, it is no longer possible to programmatically retrieve a phone number (MSISDN) on either Android nor iOS. This is due to limitations in the operating systems and not related to Fuse in any way. Programmatic extraction of such numbers were largely used for scams and malware.
If you need to know the phone number of a user, you’ll need to ask for them to input it in a text field.