How can I validate cart items in POS before checkout?

[cpBurn]

Hello all,

While in POS, I need to validate the items in the cart to allow or not the user to proceed to checkout. I created an App that subscribes to the Cart, but it only works if the user enters this App in POS. The other possible solution I was looking at is to use Cart Extension, but this doesn't allow me to modify the items in the cart.

Does anyone see a solution here?

[ryoji35997]

Same problem, does anyone have a solution?