Recovery time

New zwifter here.
How do you deal with recovery time?
It is so attempting to ride much. But overtraining is not good i quess.
In Garmin Connect i used to get recovery time after i finished a ride. Now with Zwift i don’t use my garmin 820 anymore inside.
Today i did the FTP-test which is very rough for my muscles and knees.
How long to rest?

I use my Edge 520 while on Zwift. I created an “Indoor Training” profile that has the GPS disabled and that picks up the power from my trainer. It helps with the recommendation for resting.