Flutter application not working when converted to apk

I made a small shopping application with flutter using Android studio, it retrieves the items from a database on 000webhost,it works perfectly fine on pc and even on a phone emulator on pc,but if I turn it into an apk file and send it to my phone Nothing happens when I try to login or register a new account, I’m not very familiar with flutter or hosting databases yet as I’m still learning and this is my first project. My guess is it’s not connecting to the database, any ideas how to fix it?

I don’t know what I should do or what files to attach to the post so let me know