Django admin form

#MODELO
class District(models.Model):
    """
        Ahora son llamados distritos, no ciudades
    """
    name = models.CharField(
        verbose_name=_("Name"),
        max_length=30,
        help_text=_("Name"),
        blank=False,
        null=False
    )
    ref = models.CharField(
        verbose_name=_("District code"),
        max_length=5,
        help_text=_("District code")
    )
    municipality = models.ForeignKey(
        Municipality,
        on_delete=models.CASCADE,
        null=False, blank=False,
        help_text=_("Municipality that belongs"),
        verbose_name=_("Municipality")
    )
    lat = models.FloatField(
        verbose_name=_("Latitude"),
        help_text=_("Latitude"),
        default=0.0,
    )
    lng = models.FloatField(
        verbose_name=_("Longitude"),
        help_text=_("Longitude"),
        default=0.0
    )
    area_poly = models.MultiPolygonField(
        verbose_name=_("Map area"),
        help_text=_("Map area"),
        blank=True,
        null=True
    )

    def __str__(self):
        return "{}".format(self.name)

    class Meta:
        verbose_name = _('District')
        verbose_name_plural = _('Districts')

#FORM PARA USAR EL JS CUSTOM
from leaflet.admin import LeafletGeoAdmin


class DistrictForm(LeafletGeoAdmin):
    class Media:
        js = ('/static/js/district.js',)

#JS CARGADO CORRECTAMENTE
(function($) {
    var lat = $("input[name='lat']").attr("value");
    var lng = $("input[name='lng']").attr("value");
    $("#id_area_poly-map").on('map:loadfield', function (e) {
        console.log(e.field, e.fieldid);
    });
})(django.jQuery);

#URL EN SETTINGS
admin.site.register(District, DistrictForm)