How do I use the following code to insert members of a booking into the email. I've used the code below verbatim in the email but no data comes through. I'm guessing I need to put something between the brackets but I'm not sure what.
Using the brackets like you have will never give any data as you've not given any data to pull. You need to put other tags inside, like [FIRSTNAME] and whatever else. Then the {GROUP_MEMBER} tag will populate the fields INSIDE of this tag multiple times... once for each member of the group in a detailed group registration. You have to tell it what data to include for each member though. Also, be aware that as of right now, the [ALL_FIELDS] tag does not work inside of the GROUP_MEMBER section.