how to add discount on custom option by qty in Magento 2? on add to cart magento version 2.3.4
You can not provide discounts on custom options as of now in Magento 2. By default, the discount feature works only with the final price value of the cart. However, I have come across an extension by Scommerce Mage that can integrate this feature in your store. It came in handy while providing discounts on desired custom options. You can also add conditions such as based on quantity and many more. Luckily, they also provide a free demo so if you want you can check it out here:- https://www.scommerce-mage.com/magento-2-custom-options-discount.html
Please follow below step.
- log in the admin page.
- from the left bar click CATALOG -> Products.
- Search your targeted item.
- Scroll down in the product detail and find "Customizable option"
- Add options (When you add option you can give price with negative value (example, -7) then It will be discount.