I have a test map in ArcGIS Online containing a feature polygon layer which also has attatchments uploaded. I want to edit this map in ArcGIS Pro and add new fields and fill these with information from a Excel table using a common key. Then be able to save web map and update the one in ArcGIS Online with the new information. It's not possible to use join, the new information has to be stored in the polygon and I can't replace the polygon as I will lose the attatchments.
I know how to edit the online map in ArcGIS Pro, and I managed to succesfully do this once after tinkering around a lot, but now I'm unable to recreate my own steps and solution.
I'm not sure if it matters, but when I'm editing a ArcGIS Online map in ArcGIS Pro it downloads a ArcGIS Pro Portal item and when I open this in ArcGIS Pro it's an untitled project. When I managed to do this before I think I saved the project localy at one point and added the table to the default database.
