Started to pay again, but my Nightscout app is not working

Question

guys. I cancelled my paid subscription to Heroku last month, but now I decided to keep it on, as I want to have my Nightscout account alive.

However, although I enabled the paying option, I still see an error message when I access my URL:

Any idea what else I should do to make it work again?

This is my public URL: https://sebastianhd.herokuapp.com/

Thanks for your help.