Install Vereafy App on your device by searching for it in your device’s app store.
Log in to your GitHub Account and click the top right image icon, Select “Settings” from the drop-down menu
Select the “Security” option from the menu on the left under “Personal Settings”.
Click the “Enable two-factor authentication”.
Click “Set up using an app”
Download, Print or Copy the recovery codes and click “Next”
Scan the barcode with the Vereafy app, enter the code generated from the app and click “Enable”
After clicking on the “Enable two-factor authentication” button, you are all set!