How to get the objects in a radius around my current location?

I have a models named Restaurant ,i want to fetch all the restaurant within the 3km radius of user's current location.

I am posting the model and views.

models.py

class Restaurant(models.Model):

restaurant_owner = models.ForeignKey(Account, on_delete=models.CASCADE,

related_name="restarant_details",

null=True, blank=True)

latitude = models.CharField('Latitude', max_length=30, blank=True, null=True)

longitude = models.CharField('Longitude', max_length=30, blank=True, null=True)

location = models.PointField(blank=True, null=True)

owner_name = models.CharField(max_length=200,null=True,blank=True)

restaurant_name = models.CharField(max_length=200,null=True,blank=True)

registration_no = models.CharField(max_length=200,null=True)

registration_date = models.DateField()

registration_mobile = models.CharField(max_length=200,null=True)

VIEWS.PY

class RestView(viewsets.ViewSet):

permission_classes = [IsAuthenticated,OnlyUser]

def list(self, request):

try:

radius = 2

print(self.request)

user_location=request.user.location

print(user_location)

if not user_location:

return Response({"message": "User is not Available","success":False},status=status.HTTP_400_BAD_REQUEST)

#query_set=Restaurant.objects.annotate(distance=Distance('restaurant_owner__location',user_location)).order_by('-distance')

#query_set=Restaurant.objects.filter(location__distance_lt=(user_location, Distance(km=radius)))

#query_set=Restaurant.objects.filter(restaurant_owner__location__dwithin=(user_location, Distance(mi=90)))

#query_set=Restaurant.objects.filter(location__distance_lt=(user_location,Distance(m=5000)))

#query_set=Restaurant.gis.filter(location__dwithin=(user_location, 0.008))

# max_distance = 10000 # distance in meter

# buffer_width = max_distance / 40000000. * 360. / math.cos(point.y / 360. * math.pi)

# buffered_point = point.buffer(buffer_width)

# query_set=Restaurant.objects.filter(location__distance__lte=(user_location, D(m=max_distance)),location__overlaps=buffered_point)

query_set=Restaurant.objects.filter(location__distance__lt=(user_location,Distance(km=radius)))

serializer=RestaurantSerializer(data=query_set,many=True,context={'request': self.request})

serializer.is_valid()

serializer.save()

return Response({"message": serializer.data,"success":True},status=status.HTTP_200_OK)

except Exception as e:

traceback.print_exc()

return Response({"message": str(e),"success":False,},status=status.HTTP_200_OK)