Back geocoding GRD data

Hello everyone, is it possible to do back geocoding with sentinel 1 GRD data?
Screenshot in pj

BackGeocoding is only for SLC but if you want to coregister GRD images, please select the Coregistration operator.

if I do a coregistration with the GRD data, can I do a formation interferogram to generate a DEM afterwards?
Thank you

no, DEM creation requires SLC data with suitable temporal and perpendicular baselines.
This tutorial might be interesting to you: DEM generation with Sentinel-1 - Workflow and challenges

High coherence and a clean interferogram is the most important requirement.