code: def get(self, request, invite_id, *args, **kwargs):
      iid = force_text(urlsafe_base64_decode(invite_id))
  
      # Save the clicked event
      invite_object = self.queryset.get(pk=iid)
      invite_object.invite_clicked = True
      invite_object.save()
  
      # Check if the user already exists
      try:
          user = User.objects.get(email=invite_object.to_email)
  
          try:
              Membership.objects.get(
                  project=invite_object.project, user=user
              )
          except Membership.DoesNotExist:
              Membership.objects.create(
                  project=invite_object.project, user=user
              )
  
          return Response({"existing_user": True})
      except User.DoesNotExist:
          pass
  
      return Response({"existing_user": False})
  
file_path: modelchimp/modelchimp/views/api/invitation.py
imports: from django.contrib.sites.shortcuts import get_current_site
  from django.utils.encoding import force_bytes, force_text
  from django.utils.http import urlsafe_base64_encode, urlsafe_base64_decode
  from django.template.loader import render_to_string
  from django.core.mail import EmailMessage
  from modelchimp.models.user import User
  from modelchimp.models.project import Project
  from modelchimp.models.invitation import Invitation
  from modelchimp.models.membership import Membership
  from modelchimp.serializers.invitation import InvitationSerializer
  from rest_framework import status, generics
  from rest_framework.response import Response
  from modelchimp.api_permissions import HasProjectMembership
  from rest_framework.permissions import IsAuthenticated
label_desc: Use image node_id 1 for calling the InviteInfoAPI obj's underlying member method code with example usage: obj.get(request, invite_id) and returns: Response, Response