How does one identify a Survey123 source by phone number or unique device identification? How does one add this into the Survey123 form for auto population?
This article may have some of the answers you are looking for. You would need to pull some unique identifier from the device. Note that you will need to use Survey123 Connect to build this kind of survey.
Prepopulate answers—Survey123 for ArcGIS | Documentation
Retrieving data ...