How to add products to opportunity using ABSL

Hi Experts,

I want to add products to opportunity using ABSL. Opportunity, Item and ItemProduct has write accessibility.

I can create and add new Item to Opportunity. I can create and add new ItemProduct to Item.

My problem is that I can not set ProductUUID as you see on the picture it is read only.

On Opportuinty screen when user sets ProductUUID other related fields are populated (like product id, product category).

If I set manually those fields than on product tab fields are not populated. I am only able to set Item/description and Item/quantity.

Do you know how can I add a new ItemProduct to Opportunity which refers to a product, or how can I sett ProductUUID?

Current code:

Thanks!