Django Rest Framework | Put method not working

Question

I am creating a rest api using DRF the get and post method work perfectly but the put method doesnt update the request

this is my views.py

from django.shortcuts import render
from rest_framework import viewsets

# Create your views here.
from rest_framework.generics import get_object_or_404
from rest_framework.response import Response

from BarakaSalesSystemApp.models import Farmer
from BarakaSalesSystemApp.serializers import FarmerSerializer

def list(self, request):
    farmer = Farmer.objects.all()
    serializer = FarmerSerializer(farmer, many=True, context={"request": request})
    response_dict = {"error": False, "message": "All Farmers List Data", "data": serializer.data}

    return Response(response_dict)

def create(self, request):
    try:
        serializer = FarmerSerializer(data=request.data, context={"request": request})
        serializer.is_valid(raise_exception=True)
        serializer.save()
        dict_response = {"error": False, "message": "Farmers Data Saved Successfully"}
    except:
        dict_response = {"error": True, "message": "Error During Saving Farmers Data"}

    return Response(dict_response)

def update(self, request, pk=None):
    try:
        queryset = Farmer.objects.all()
        farmer = get_object_or_404(queryset, pk=pk)
        serializer = FarmerSerializer(farmer, data=request.data, context={"request": request})
        serializer.is_valid(raise_exception=True)
        serializer.save()
        dict_response = {"error": False, "message": "Successfully Updated Farmer Data"}
    except:
        dict_response = {"error": True, "message": "Error During Updating Farmer Data"}

    return Response(dict_response)


farmer_list = FarmerViewSet.as_view({"get": "list"})
farmer_create = FarmerViewSet.as_view({"post": "create"})
farmer_update = FarmerViewSet.as_view({"put": "update"})

and this is my serializer.py

from rest_framework import serializers
from BarakaSalesSystemApp.models import Farmer, Customer, Order, Bill, Employee, Delivery
class FarmerSerializer(serializers.ModelSerializer):
class Meta:
    model = Farmer
    fields = ["name", "address", "contact", "in_stock"]

When requesting for the put request on postman it gives the error message and not updating