Q.when are passion flower seeds ready to pick
I want to start the passion flower vine from seed. When is the fruit ready for harvest and how do I tell if seeds are ready?

The fruit will change from green to yellow or purple depending on the variety. The fruit will drop from the vine when ripe.
Here are some links to help you.
https://www.gardeningknowhow.com/ornamental/vines/passion-flower/propagating-passion-flower.htm
https://www.gardeningknowhow.com/ornamental/vines/passion-flower/passion-flower-care.htm
https://www.gardeningknowhow.com/ornamental/vines/passion-flower/passion-flower-not-fruiting.htm