I set up nextcloud per the instructions I shared. Thanks much to the author for well written instructions.
I still ran into some trouble. When I set up auto upload, it created a folder called “instantupload” and syncronized the local “pictures” folder to that folder along with the other folders I set to auto upload.
The original “pictures” folder that was syncronizing with the local “pictures” folder until I added pictures to it manually was still there but still was not syncronizing.
I am not sure but my conclusion is that when I manually added photos to the the “pictures” folder in my e cloude from my pc, it somehow broke the link between it and the local “pictures” folder on my phone. The nextcloud seems to have made a new “pictures” folder under the “instantupload” folder that is now synced. I deleted the original “pictures” folder using the nextcloud app and I think I am all set now. We shall see.