How do u delete a purchase history?

You can't delete items from your purchase history but you can hide them.

For apps, see this document: Hide purchases from the App Store - Apple Support .

It only mentions hiding apps but according to Apple (as Recommended in: how do i delete an expired subscription - Apple Community ) subscriptions get hidden too.

Read this document about hiding music, movies, TV shows, audiobooks, and books - Hide and unhide music, movies, TV shows, audiobooks, and books - Apple Support

This doesn't remove the item in your purchase history but Family Sharing members won't see them and they won't appear in your Library on a device unless you downloaded it to a device.

There is no option to delete history but you can hide purchase history. See: Hide purchases from the App Store - Apple Support