After logging in, click on your name/initials located at the top right of the page, then click on 'Applications'. You will see the app integration page.
Click on 'Connect' and follow the prompts to authorize Figshare to access your GitHub. Once completed, go to My Data and click on the GitHub icon (next to "Create a new item")
You can then start importing from GitHub from your list of public repositories:
See this page for more information on how GitHub records can be automatically synced with your SMU RDR.