This is the one I use. It is pretty cheap and has a good rating on Amazon. It is really easy to take the phone out of the case. I use the case when I go out but I use the phone without the case when I am at home.

If you don’t mind spending more money, Apple has a smart battery case for around 100 dollars. You can find that here It says iPhone 7 on the site but it works with the iPhone 8 and iPhone SE 2020.