There is an answer to my first question that I tried to do.
I created virtual-env local repository, where I installed requirements.txt with: git+https://github.com/ramusus/kinopoiskpy@refs/pull/47/merge#egg=kinopoiskpy.

It was installed successfully, although there was WARNING: Did not find branch or tag.
And then I tried to push requirements.txt to my Heroku server and re-deploy.

And I don't even know what's the problem. What should I do to fix this?