NAD83 is a datum, not a coordinate system. Do you want projected or geographic coordinates in that datum?
Yes Dan, NAD83 is a datum. I know that GPS uses WGS84 datum so Survey123 can display coordinates with different coordinate systems like DD, DMS and UTM, all being in WGS84. I wonder if Survey123 has the capability to transform the GPS coordinates from WGS84 to NAD83. For my purpose I'd like to have geographic coordinates DD in NAD83. But if Survey123 could transform from WGS84 to NAD83 I think that it will not be a problem to display coordinates in DD, DMS or UTM NAD83. Therefore the main issue is to transform from WGS84 to NAD83...
Perhaps these threads no longer apply, but the suggestion is to do coordinate conversion outside
Coordinate System Survey123 Stores Data In
https://community.esri.com/thread/230580-what-happens-to-a-second-geopoint-question
I had a similar issue where I was writing submitted survey records to another feature service in NAD 83 state plane, and my points were being plotted incorrectly. I discovered that geopoint questions will always be in WGS84, and there is no way to convert them within Survey123. However, you can use webhooks to pass the point information to another feature service published in the desired coordinate system. There is a parameter to transform the data when doing an applyEdits operation using the ArcGIS REST API. The transformation can be automatically processed using webhooks and an automated services platform such as Power Automate or Integromat. Optionally, you could also leverage a geometry server service (Services>Utilities on your server's REST endpoint or by using https://utility.arcgisonline.com/arcgis/rest/services/Geometry/GeometryServer/project?) and use the built-in project operation using the ArcGIS REST API.