Dunno if there are any front-cover only options, but I bought this for my Air and it's perfect. I'm sure there's a non-Air version.

https://www.amazon.com/dp/B07HQCDYTK?psc=1&ref=ppx_yo2ov_dt_b_product_details

But yeah it's basically apple's smart folio, but like 20% of the price.