Fix ICloud full with out any file in it

Your iPhone may tell you that iCoud is almost full but there is no file in your phone. Try to check you storage manager and look at the back up setting, sometimes iPhone try to back up things that you don’t want it to. And it made your iCloud full, fast. Remove it from your back up setting and then make a new backup. In my case, i remove Onedrive from the back up setting and storage reduce to less than 100 mb

Settings > Apple ID > iCloud > Manage Storage