Mongoose-slug-plugin is it possible to add your own slug term while maintaining uniqueness?

Question

Node.js

I use this lib for the slug field, made the slug field unique, after saving the object this field is added and in general everything https://www.npmjs.com/package/mongoose-slug-plugin
From the client I get the slug field, user option , how to insert this line into the slug in the Mongoose model and check for uniqueness?