Automatically Apply Discount in chekcout without code using api call or custom checkout botton

Hello everyone!

I am working on Shopify apps. I want to automatically apply a discount on the checkout page without a discount code like the above image based on a specific user and product.

Any idea I can I do that?
which Api should I need to call?

This doesn’t look like a discount but the product price and the product compare at price.
You will need to update the product listing to do this, BUT this will change the prices for all users!

yeah, you are right then the product price will change for all users.
But this is a discount without a code.