Hey, @Wakira👋 Thanks for reaching out. Can you tell the community where you are getting stuck? For example, can you create the webhook subscription for your app, but not add the custom property?
I created a custom ticket property called — Cat Circus Booking, and noted the internal name for the property cat_circus_booking
Went to my app > Webhooks > Create subscription
Here's the subscription
If you are trying something different or getting an error, please add additional details. This helps the community to better understand your roadblock.