If you wish to link your MyCrohnsandColitisTeam account with your Facebook account, you must first sign up via Facebook. Click "Sign up with Facebook" and go through the sign up process.
When you go to sign in on the homepage, click the Sign in with Facebook prompt.
You will be directed to log in with your email address and password for Facebook.
If you have any questions about this feature, please feel free to contact Support here.