How can I make postal code entry mandatory during checkout?

[gadoda]

Hey,

when a customer make a reservation he need to fill few things.

one of them is “postalcode”.

but there is a problem,

if the customer keep this blank so shopify will let him and the order will go fine.

if the customer write something so shopify will not let him to write a postalcode thats not fit to the normal postalcode to the area.

i need to know how can i make the postalcode to be necessary so if the customer keep it blank hewont be able to finish the order.

thank you.

[gadoda]

Hey,

First of all, thank you so much for your answer.

Second, i did not found what you say as “cart.liquid”.

The only one that looks like it is: “gift_card.liquid”.

im upload a photo so you can look.

thank you again.