Adding prices to Line Item Properties (exist example site)

Shopify Apps
1

Hi,

I would like to add a price to the product option in the “main-product.liquid” file using the properties.
I read almost all of the questions and answers about the topic in the Shopify Community, but I couldn’t find answer.

I’m kind a new with Shopify, so please if someone know how to implement this, please help me out.

I know how to use line item properties. (https://easycodeguide.com/how-to-add-custom-properties-to-product-page-on-shopify.html)

However, I found several sites where product properties can fix prices in cart page.

  1. https://mysppteststore.myshopify.com/admin/themes/122623000708?key=sections%2Fmain-product.liquid
  2. https://dynamic-product-options-demo-store.myshopify.com/products/computer-dpo-example-2

What I tried:

  1. Fetch to create product variant at front-end → ERR_TOO_MANY_REDIRECTS
  2. Use an endpoint of custom-app → Cors issue from front-side

Please anyone just give me a hint!

Thank you for you time.