How to add new coupon by owner
To add a new coupon, go to Dashboard → Coupons and click Add New Coupon. The opening screen will present you with the coupon code and other settings.
How to set up a coupon widget
If you would like to display a widget with coupon code and description first you have to add Coupon Widget in Appearance → Widgets for Single Listing Page
Then you can select specific coupon and enable widget for each listing in listing editor:
Managing coupons
From WordPress admin in WooCoomerce. Navigate to WP Admin → Marketing → Coupons. You can manage there both user coupons and own created by site admin.
Coupons do not work
If after all steps above you still can’t see coupons in listing pages and add listing form most likely you disabled them in Listeo Core → Booking → Remove Coupons option from Booking widget and confirmation