Hello there,
I believe for great potential for the ArcGIS for Excel, but I'm not sure what is the best way to integrate it between ArcGIS Pro and Excel for polygons.
Because, for points, it's not a big deal (it requires extracting X and Y). For polygons - We have to collect it by geometry by .geojson (text) format - it's fine but...
How to do that?

Any web tutorials go to suggest the WKT format, but I believe it should be possible to do that for .geojson format is only way for the plugin.
My suggestion goes to two steps:
1. Export geometry to text (into attribute)
2. Save feature table into CSV/XSLX like below

I don't sure what's steps should be done in ArcGIS Pro?
Thanks for any advice