How to assign the same id to multiple objects in mongoose?

I want to assign the same id value to roomID where the objects have the same type.

const Item = new Schema({
  roomID: { type: String},
  type: { type: String }
});

const Order = new Schema({
  items: [{ type: Item }]
});

I want the output to be something like this:

{
  id: "1234567890",
  items: [
    {
      roomID:"5efd1db1803ec01b1c590e23"
      type: "first",
      // more data
    },
    {
      roomID:"5efd1db1803ec01b1c590e23"
      type: "first",
      // more data
    },
    {
      roomID:"5efd1db1803ec01b1c590e82"
      type: "second",
      // more data
    },
  ],
};