To add the book a Teams meeting feature to your CodeTwo signature you need to first setup your Bookings page. Go to the link below. Bookings - Outlook (office.com)
You will then see the below page. Please click Share on the right-hand side of the screen, then Copy link. Now you have copied the link to your personal Bookings page please go to the link below. CodeTwo User Portal
If prompted please login with your goodfellow email address and password. You will then be presented with the page below please paste your personal bookings page link into the text box and click save & update. Now to test your signature compose a new email in Outlook and you should see "Book a meeting with me" in your signature.