App runs locally but not on Heroku

Hello everyone!
I’ve been struggling with this for a while. I have app
which runs fine locally. It loads on Heroku but most of the functions do not work (graphs is not loading for example). I suspect there is some problem with mongodb but there are no errors in Heroku logs.
Any help is appreciated.

You shouldn’t publish your database password on GitHub (See: use enviroment variables for that. Now anyone can at will harm your database and we don’t want that.