How to add your properties to the cart and then to the Bitrix order?

Question

1C-Bitrix

Help!
There is a catalog item, and a standard bootstrap template.
I add my property in the template itself. How can I pass it to the cart and to the order? I created an element property (I don’t know if it’s necessary or not), it is empty or can be filled, and then on the element page, when you click on the checkbox, its value changes (I did it through JS), but then how to send it changed to the trash? It is necessary to transfer only the text and everything that does not affect anything. Who will tell?

<input type="checkbox" name="fitted" value="ДА"/>

Answer 1

Expand the store demo and see how it's done there.