Bought Peach Pass at CVS; tie to existing account

Just bought a new car. I already have a family Peach Pass account. How do I tie the new transponder into my existing account?

I've seen something on Reddit that suggests this can't be done.

I couldn't get support on this over the past weekend. They were closed for MLK yesterday. Closed for cold weather today. System goes down for an upgrade later this week.

Bad timing for me, I guess.