Sorry I included the https:// in the virtual host tick box. But when I removed it and replaced it with the one in the image, The ERROR I get is :
CRIT - Unable to open https://stage.mydomain.com/https://stage.mydomain.com/admin/index.php/login/user_validation: [404] HTTP Error 404: Not Found
The page with a User and Password login requirement is “https://stage.mydomain.com/admin/”