Configuring application wide integration settings for GitHub in Test Collab:
While providing "URL for issue manager" make sure you enter https://api.github.com instead of https://github.com followed by username (or email) and password and fields (if required to be provided global values).
You also have an option of allowing the reported issue to be resolved automatically when the related test case passes by checking "Resolve reported issues when a failed test case is marked as passed". When you check this you will be prompted to provide the status code that Github uses for resolved issues, you need to enter the same for "Status code for resolved".
Project wise integration settings
When it comes to project specific settings, values for following fields can be provided:
Repository name - the repository to which you want the bugs to be reported in case of a test failure
Github name of owner of repository - GitHub username
Assignee - User who should be assigned the automatically created bugs
You can also add other fields including any custom field using "Add user defined field" from the drop down, clicking this you will get a text box in place of drop down to enter the name of the field.
A completed project specific issue manager setting form for GitHub would look like this.
For "Labels" field you may provide value from these
Once the values for all fields have been provided you can save and test the settings by creating a sample issue in GitHub.