In case you want to allow your affiliate to choose their own coupons, you can ask them to fill in their preferred coupon on the registration form, then assign proper coupon to your team later. To get this work done, there are two options for you:
After having your affiliates' opinion about their favorite coupon, you can see all the details that your member filled in on Affiliate & coupon tab, then manually create and assign each coupon for each affiliate following the instruction about Tracking by coupon.
However, manually task sometime could be time-consuming especially when you have two many affiliates, so our recommendation would be: let the work done automatically
Basically, there are 1 simple step you need to do to get it work: set up auto-generate coupon feature.
Go to Settings => General => Turn on Auto-generate coupon then click Setup coupon.
Firstly, create a sample coupon whose rule you want future auto-generate coupons to follow.
On Coupon Name's Style, select Affiliates choose while registering
Fill in a short description for the coupon, then click Add.
After activating the feature, a Coupon field will be auto-created on your registration form and will be marked as required. So your affiliate must enter their preferred coupon upon signing up.
Also, if your affiliate choose an coupon that is already exists on your shop, there would be a notification for them to change to another.