DRF detailed information of user in related serializer

My question was: How can I improve this detailed view of a contributor?

# serializers.py

class ContributorDetailSerializer(serializers.ModelSerializer):

    class Meta:
        model = Contributor
        fields = ["id", "user"]

result in Postman:

---

My contributor model has just one attribute: user a ForeignKey relation to the user model.

# models.py

class User(AbstractUser):
    pass

    def __str__(self):
        return self.username


class Contributor(models.Model):

    user = models.ForeignKey(
        "api.User",
        on_delete=models.CASCADE,
        related_name="users",
        verbose_name=_("user"),
    )

    def __str__(self):
        return self.user.username

---

There are several possibilities, I want to show two different approaches:

first example:
using the __str__ method of the user model

# serializers.py

class ContributorDetailSerializer(serializers.ModelSerializer):
    user = serializers.StringRelatedField()

    class Meta:
        model = Contributor
        fields = ["id", "user"]

result in Postman:

user = serializers.StringRelatedField() is displaying the __str__ method of the user model. As you can see above in the __str__ method in user model, it returns the username of the user.

second example
display all information of an other Serializer

# serializers.py

class ContributorDetailSerializer(serializers.ModelSerializer):
    user = UserSerializer(read_only=True)

    class Meta:
        model = Contributor
        fields = ["id", "user"]

result in Postman:

user = UserSerializer(read_only=True) takes all the attributes of UserSerializer and adds them to the ContributorSerializer attribute user and display all information.