I have a hosted feature layer that also has a related table I used the following Demo Video by ESRI Ireland to set it up - Designing Related Records in ArcGIS Pro for use in ArcGIS Online - YouTube .
I want to now create a survey that can add records to the related table that get included back to the correct parent feature in the map. Easy example, if I have a layer of stop signs with ID's and a related table with inspection records. I want the survey to populate a new inspection record that references the ID of the Stop Sign so that when I click on the Stop Sign in any Map product that survey inspection table record is included on that asset.
I've been able to create a survey in S123 Connect with the feature service option and selecting the stop sign layer. then following the directions below create a survey that does populate a new record in the related table but does not attach itself to any features.
Given that you posted in a response from another post, I'm not quite sure where you are needing help. Is it at:
1) Creating the survey for the related records
2) Creating a hyperlink to open the survey and populate the parent's information in the form?