Overlay Availability option Not available?

I got an email about an Overlay Availability option, where clients could overlay their calendar into the app and make it easier to fit things into their schedule, however, this function is not apparently available to me.

I’m using the iframe version of the appointment book with the options set up as follows for the booking times:

Any clues on why it’s not available?

@mactax I will send you a message so you can share your embed. On the embed things may not work if you are hiding the header and also with cross domain functionality. I’ll double check things with the team.