Rein here from Shopify. I see you are looking for a way to offer discounts based on the payment gateway selected at checkout.
There would actually be no way to directly manage that within Shopify. What I would suggest is perhaps utilizing some sort of promotional rebate system whereby you refund X% depending on the gateway chosen manually.
Connect your PayPal account to allow your customers to checkout using the PayPal gateway a...By Ollie Jul 28, 2022