GitHub client: Pull Request Button is missing

I use GitHub client for Bitbucket repository. All work & sync correctly, but Pull Request button not showing. In GitHub repo all works.

I found simular issue - Github for Mac: Pull Request Button is missing, but I use Bitbucket and can't change repo marker from "other".

Any proposal?

GitHub:

Other repo:

Answer from official github support ( support@github.com ):

In order to create a pull request the repository must exist on GitHub.com.

and

There is a button called 'View Branch' beside the update from master button.

If you click this, the 'View from Master' button should change to 'Compare'.

If you click this button you should see a list of branches you can choose from to merge!