ggfat

This plugin automatically offers a discount coupon for every purchase made by setting a expiration date in days. 
This plugin manages to automatically give customers a coupon for each purchase they do so as to entice them to make the next purchase. You can set the discount percentage, the days of validity, the description of the coupon and you can send everything via email. Then you can enter the subject and body of the email.
Truly wonderful.

WC Give a Coupon

Grazie a questo plugin sono riuscito a dare automaticamente ai miei clienti un coupon per ogni acquisto che facevano così da invogliarli a fare il prossimo acquisto.

Wonderful

A plugin that automatically offers a discount coupon for every purchase made by setting a deadline.

WC Give a Coupon vs Ultimate Gift Cards for WooCommerce