Thanks to a previous question I was able to update an assignments integration_data using :
assignment[integration_data]={"id":1XXXX,"heading":"My Heading"}
Now I need to do the same for an assignment group but none of the following variations have worked :
assignment_group[integration_data]={"id":1XXXX,"heading":"My Heading"}
assignment_groups[integration_data]={"id":1XXXX,"heading":"My Heading"}
integration_data={"id":1XXXX,"heading":"My Heading"}
I'm hoping someone here can point me in the right direction.