КЛАСС USER

class User(AbstractBaseUser):
    phone_number = models.CharField(max_length=11, unique=True)
    first_name = models.CharField(max_length=30, blank=True)
    is_active = models.BooleanField(('is_active'), default=True)

    objects = UserManager()

    USERNAME_FIELD = 'phone_number'

    def save(self, *args, **kwargs):
        super(User, self).save(*args, **kwargs)
        return self


class UserManager(BaseUserManager):

    def _create_user(self, phone_number, password, **extra_fields):
        if not phone_number:
            raise ValueError('The given email must be set')
        try:
            with transaction.atomic():
                user = self.model(phone_number=phone_number, **extra_fields)
                user.set_password(password)
                user.save(using=self._db)
                return user
        except:
            raise


ПЕРЕПИСАННЫЙ МНОЙ СЕРИАЛАЙЗЕР

User = get_user_model()
jwt_payload_handler = api_settings.JWT_PAYLOAD_HANDLER
jwt_encode_handler = api_settings.JWT_ENCODE_HANDLER
jwt_decode_handler = api_settings.JWT_DECODE_HANDLER
jwt_get_username_from_payload = api_settings.JWT_PAYLOAD_GET_USERNAME_HANDLER


class CustomJWTSerializer(JSONWebTokenSerializer):
    username_field = 'phone_number'

    def validate(self, attrs):

        password = attrs.get("password")
        user_obj = User.objects.filter(phone_number=attrs.get("phone_number")).first()
        if user_obj is not None:
            credentials = {
                'username': user_obj.username,
                'password': password
            }
            if all(credentials.values()):
                user = authenticate(**credentials)
                if user:
                    if not user.is_active:
                        msg = _('User account is disabled.')
                        raise serializers.ValidationError(msg)

                    payload = jwt_payload_handler(user)

                    return {
                        'token': jwt_encode_handler(payload),
                        'user': user
                    }
                else:
                    msg = _('Unable to log in with provided credentials.')
                    raise serializers.ValidationError(msg)

            else:
                msg = _('Must include "{username_field}" and "password".')
                msg = msg.format(username_field=self.username_field)
                raise serializers.ValidationError(msg)

        else:
            msg = _('Account with this email/username does not exists')
            raise serializers.ValidationError(msg)