If you have updated your iPhone to iOS 13 you might notice that downloads in Safari work quite differently - downloads now go into the Files app > Downloads folder. And then you should be able to Share the EPUB file using the "Copy to Equipd Bible" option from the Share menu (once you have enabled it). However for some reason that will just switch to the Equipd Bible app, but not actually install the file. Temporary Solution Until I get a chance to work out why this option does not work as expected in the Files app, the good news is that the Share option "Copy to Equipd Bible" seems to work from everywhere else! Weird. So if you can download the EPUB file into another program such as Documents by Readdle, or the Google Chrome Browser app, and then use the Share button to "Copy to Equipd Bible" then it should work as expected. I am sure that many other apps will work as well. Below is the link to a very quick recording of using the Google Chrome app to install the NWT Chinese Mandarin EPUB file.