How to make travis ci and heroku friends?

Question

Heroku

I am studying the topic of ci / cd, I did some time ago on this article for a test project. Everything worked until recently. Now errors are coming out and deploy is crashing.

No stash entries found.
API request failed.
Message: Invalid credentials provided.
Reference: 
failed to deploy

Perhaps travis ci changed something in the documentation or something else. Please tell me what exactly is outdated in the article (what needs to be changed).

My config file

language: node_js
node_js:
  - 10
branches:
  only:
    - master
deploy:
  provider: heroku
  app: my-react-burger
  api_key:
    secure: HEROKU_API_KEY
after_success:
  - cat ./coverage/lcov.info | ./node_modules/codecov.io/bin/codecov.io.js
  - cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js

ps api key set as HEROKU_API_KEY, $HEROKU_API_KEYand even directly - it still crashes. Maybe that's not the point.