Hi,
When you create an offer in front or back-end, in the form there is a field named "Coupons number". In that field you put the number of coupons you wish to be generated by the offer. After saving, go to see it and notice the button on the right-top under the share link "Get this deal" . A generated coupon(pdf file)is available to see it in Control panel/Coupons
Hope it helps Not an official answer.