The app is dead that's the first thing you should know.
It's real dead now. I was getting (actually scrapping data from vus.daffodilvarsity.edu.bd) which is dead. And thus this is dead and I think will remain dead.
I have no connection or whatsoever to authority for getting data from database. and the google reCaptcha v2.0+ is not bypassable (as of now). Therefore this app cannot get you data from student portal by scrapping.
However if you find any access to database you can use this as a skeleton app. Maybe let me know!! And make a pull request if you want my repo to have the latest update.
This is the Android implementation for https://github.com/mehedi-shafi/DIU-Result-Sheet this project. Look into the README there. And WIKI as well for how things work.
Read the Wiki before asking questions.