So I'm trying to make a simple GET API that should list all Users with a role:'admin' This is mongoose Schema for User:

const userSchema = new mongoose.Schema(
  {
    username: {
      type: String,
      lowercase: true,
      minlength: 3,
      maxlength: 20,
      required: true
},
 role: {
      type: String,
      enum: ['admin', 'doctor'],
      required: true
    }});

But I have no idea how to get value 'admin' from role.