YITH Badge Management allows you to create custom badges for your products where you can show discounts, labels etc.
If used with YITH Multi Vendor also your vendors will be able to create their own badges and apply them to their own products.
After installing and activating YITH Badge Management, just make sure you enable the option Create and manage badges for their products in YITH > Multi Vendor > Vendors > Vendors Permissions.
Now, your vendors can see a Badges menu in their dashboard to create and manage the badges for their products.
For more details about YITH Badge Management and how to set up a badge, please, refer to the plugin documentation.