This is called affiliate marketing.
You can find some here https://apps.shopify.com/browse/marketing-affiliate-programs
Hi @kllyklly, I'm Neomi from Rise.ai app.
we are an app specialized in store credit rewards and gift cards to help you maximize revenue and loyalty at your store.
We are about to release our referral program next month and we are looking for beta testers.
If you are interested you can reach me an email@example.com