How to setup Survey123 to write to an existing feature layer on AGOL?

[NickToscano]

Do I need to create the survey and then switch out the feature layer that is there with another one in the folder?

[JamesTedrick]

Hi Nick,

It's better to create a survey from your existing feature service already.  Use Survey123 with ArcGIS Server—Survey123 for ArcGIS | ArcGIS  Describes using Survey123 with existing services.