I am trying to configure Sentry addon on Heroku and I get an error
Encoding error. Please ensure that all data in the request can be interpreted as UTF-8.
I tried both command line and using the dashboard in the browser. I have checked my account settings and don't use any non - English characters.
As noted by Markus Unterwaditzer in the notes to the question, it seems it was an issue with Sentry. I can now confirm that it works.