How can I track sales through referral codes in Shopify?

Hi! I am new to Shopify. Within my business, I will have representatives who will direct others to my web site to buy my products. I would like to give those reps a CODE so that I can track which reps bring in sales, as this is how I will pay them a commission. Not a coupon code, just the ability to attach sales to a particular person who provides that referral. Thank you

Do not mistake the advertising purpose, because this app is not mine, and I am using it, you can search for any other Affiliate app, but I feel this app is easy to use compared to other apps I have used

https://apps.shopify.com/goaffpro