Unable to combine discounts using rest API

[Otpculture]

Hi,

Is there anyone who can help me to create a discount code by REST API and make combined discount option selected?

I already tried the price rule link to create the discount : https://shopify.dev/docs/api/admin-rest/2023-04/resources/pricerule#create-2020-10

and not able to find the key for the combined discount, I have created multiple item-wise discounts and should be able to apply multiple on checkout but it's just overriding and applying only one last discount code.. How I can apply all the discounts at once?

Please check attached file, I want to make that option enable. 

My script is in PHP and it's totally backend process, so do not share any frontend solution.

Thank you.