With YITH Multi Vendor, you can turn your e-commerce store into a marketplace (a multi-vendor platform) like Amazon or Etsy and earn commissions on orders generated by your vendors.
When used with YITH Name Your Price, vendors will be able to enable this option on one or more of their products and let users choose the price (also between minimum and maximum values, if they want to).
Make sure you have installed and activated both plugins. Then, select “Name Your Price” products in the option Vendor can sell available in YITH > Multi Vendor > Vendors > Vendors permissions.

The vendor can then see a new Name Your Price menu where they can create customized price rules for product categories.

Moreover, just like the admin, they can enable the Name your price option from the single product settings to enable it on specific products only.

For more details about YITH WooCommerce Multi Vendor plugin, please refer to the plugin documentation.