Settings reference

Each rule has these fields (Marketing → Auto Coupons → Create Rule):

Field	Default	Notes
Name	—	Required.
Description	empty	Optional.
Trigger	—	First Order, Nth Order, Minimum Order Amount, Order Completed.
Trigger Value	0	Nth Order: the order number. Minimum Order Amount: amount in paise.
Discount Type	Percentage	Percentage (%) or Fixed Amount.
Discount Value	—	Percentage: 100 = 1%. Fixed: paise.
Min Order	0	Smallest cart for using the code, in paise. 0 = none.
Coupon Prefix	AUTO	Codes look like `PREFIX-XXXX-XXXX`.
Max Uses	1	Total uses of each code. Each customer can use it once.
Valid Days	—	Days until each code expires.
Send coupon via email	On	Email the code to the customer.
Status	Active	Disabled rules create no codes.

Other places that matter:

Settings → Communications → Email Templates → Auto Coupon — the email's wording.
Settings → Communications → Email Logs — check the coupon emails were sent.
Marketing → Promotions — each code also appears here as a coupon, with its usage.