How to delete purchase history permanently

Hi, karineravanda.

It isn't possible to clear or delete your purchase history. The closest thing to that would be to hide purchases as outlined here:

"Hide apps on your iPhone, iPad, or iPod touch

1. Open the App Store app.
2. Tap the account button , or your photo or initials, at the top of the screen.
3. Tap Purchased. If you use Family Sharing, tap My Purchases.
4. 
5. Find the app that you want, then swipe left on it and tap Hide.
6. 
7. Tap Done.

"

Hide purchases from the App Store - Apple Support

We hope this helps you out.

Cheers.