I am unable to integrate source control i.e., fork the repository GitHub .!

[Abdur Rahman1]

Good evening.
I hope you are doing well.!

Question: Create an Application with a table extending Task, integrate the source control and create a branch with Application Properties and create a System property module to your application. Create a system property “assignment.group.priority.critical”, then use the system property to set the default value of the Assignment group as ‘Help Desk’ when the priority is ‘Critical’. Commit the changes in the source control.

Here, I am unable to integrate source control i.e., fork the GitHub repository to my ServiceNow instance. I am getting an error as "Repository authentication failed, check credentials. Make sure the user has both read and write access".
Please check the below screenshots.
I have given my GitHub email ID and GitHub password as my credential.
How should I resolve this error?
Also, please explain me in brief how to move ahead with the question once the error is resolved. 

Thank you.

[Abdur Rahman1]

Thank you so much Sandeep. The issue got resolved. I was stuck with this issue for the last 2 weeks.

[Abdur Rahman1]

And Sandeep, (The GitHub fork issue got resolved.) now please tell me how to move ahead with the question.