Moving discussion over to https://community.esri.com/t5/arcgis-online-questions/how-can-i-add-a-legend-to-my-360-vr-experience...
Please don't double post
Understood. You can delete this post.
When I need to do this I edit the ground image layer and put my legend on it.
I was thinking of doing this too but couldn't find how. How do you use an image as the ground layer?