Adonis v5 relationships

I'm trying to create a relationship between a City and a Person table in Adonis v5, so when i request the server to show a person, it would send as response the Person and the City object that is related to that Person. I already did a foreign key relationship in my pgdatabase.

Doing some research, I found that in Adonis v4 it would be something like this:

And this would be the index() response:

How can I do the same thing with Adonis v5? .with() does not work the same way in Adonis v5, so I don't know how to use it.

This is what I have done so far:

export default class Person extends BaseModel {

  @belongsTo(() => City)
  public city: BelongsTo<typeof City>
  ...
}


export default class PeopleController {

    public async index() {
        const people = await Person.all();
        return people;
    }
}

Sorry about the long post and thanks in advance.