GRAN FONDO TRAINING PLAN

Hello!

i just started again on zwift, to get training for a race than will be held on 2 of September, i have been training, but now i want to take part of the zwift gran fondo training plan.

The issue is that i want to take the last 3 weeks, and it only allows me to take the 5 last weeks.

how can i set up the race date to get enrollment into the plan?