Go to the Github website .
Click the Sign in button:
Specify a Github username and a password in the corresponding Username or email address and Password fields:
Click an icon of your profile:
Press the Settings button:
Navigate to the SSH and GPG keys tab:
Click the New SSH key button:
Log in to your Plesk control panel.
Go to Domains > example.com > Git.
Note: Change the "example.com" domain in the path above to the correct one.
Make sure that the Remote Git hosting like GitHub or BitBucket tab is selected:
Specify the private repository name, e.g.:
git@github.com:johndoe/test.git
in the Remote Git repository field:
Copy the content of the SSH public key field:
Back to the Github website, specify the key name in the Title field, insert the copied key from Plesk to the Key field and press the Add SSH key button:
Come back to Plesk and press the OK button to clone the private repository.
example.com and the example repository URL
with your actual domain and private GitHub repository.