Adding optional product cost to products WooCommerce

I really need to add an optional checkbox to our products and I don't know how to do it.

I made custom single product pages in Elementor (free version). I would like to add an additional product cost option that needs to show up in cart. Let's say I want it to look something like (checkbox) Assembly in 14 days -170€. I'd also "assembly" part to have a description below saying "Space needs to be pre-prepared.".

I tried a few plugins and I never got the desired result. I think the best way to do it would be by creating a shortcode, so I could implement it in Elementor.

You can see an example of my custom product page here: https://moja-savna.si/trgovina/apollon/

I hope someone can help me out with this.

Thank you for your time!