May have missed this, but does anyone know...

If there's 2 of us going together but we can only buy one ticket individually (so I can't buy my family member's at the same time on my account, unless I log in separately as him), is there a way to link the our separate purchases together (so to speak) so we will end up next to each other come game day ?

I've heard there's a Group ID function but can't seem to find anything more about it online ?

Grateful for any help and guidance.