How do I reinstall my Safari app on my iPhone?

Are you sure it's gone? It seems strange that Safari has been deleted.

Check in Settings -> Screen Time -> Content & Privacy Restrictions -> Allowed Apps if Safari has been disabled.

Alternatively check if you have installed a Profiles & Device Management in Settings -> General

You browse the safari in your app Apple store and you reinstall it.

You don't. Safari is part of iOS and cannot be removed. It can only be hidden using screen time or a management profile.