Shopify app unresponsive after heroku deployment

[Droppx]

Hi, 

My app works fine when I run it locally from my code editor (shopify.bat serve) but when I deploy to heroku, and I click the link, I get this 

Also, when I open the app from any store, the page becomes unresponsive 

I saw a similar post and it was solved by committing the code and then "git push heroku master". 

I have done that as well but it doesn't help

I have also put in all env variables in heroku as you can see below.

I don't know what I am doing wrong. Please I will appreciate any help, thanks

[DGC]

Assuming the app works when you go to the url directly, has it gone to sleep?

Are you on the Free tier? That tier sleeps after 30 mins I think