Checkout verification, but I want to do it in PHP

https://shopify.dev/docs/apps/checkout/validation/server-side

Cart and checkout validation using js, but can I validate checkout using PHP?
I looked at the documentation but could not figure it out.

The image has added validation in js according to the documentation.
I would like to do this in PHP.

Hi Tera3,

Currently Shopify Functions don’t support PHP so you’ll need to work with either JavaScript, TypeScript, Rust, or Wasm.

@Liam

Thank you. By the way, is it possible to validate the cart using anything other than Shopify Functions?
We are looking to develop a feature that will only allow members to purchase member-only products.