Как во время изменения формы сформировать уведомление о изменении и отправить его группе

Как во время изменения формы сформировать уведомление о изменении и отправить его группе?

Есть views

def timetable(request):
timetab = ClassModel.objects.all()
context = {"timetab": timetab}
return render(request, "admin/timetable.html", context)


def revise_timetable(request, pk):
    try:
        rev_timetable = get_object_or_404(ClassModel, pk=pk)
        if request.method == 'POST':
            form = ClassModelForm(request.POST, instance=rev_timetable)
            if form.is_valid():
                post = form.save(commit=False)
                post.save()
                return HttpResponseRedirect("../../timetable")
        else:
           form = ClassModelForm(instance=rev_timetable)
       return render(request, "admin/revise_timetable.html", {"rev_timetable": rev_timetable, 'form': 
 form})

   except ClassModel.DoesNotExist:
        return HttpResponseNotFound("<h2>not found</h2>")

models

class GroupModel(models.Model): # Группа
students = models.ManyToManyField(AdvUser)
teacher = models.ForeignKey(AdvUser, verbose_name='Учитель', on_delete=models.CASCADE, 
related_name='groups_teacher', default=None)
course = models.ForeignKey(CourseUser, verbose_name='Курс', on_delete=models.CASCADE, 
related_name='groups', default=None)
title = models.CharField('Название', max_length=100, blank=True)
slug = models.SlugField(max_length=100, db_index=True, default=None)


def __str__(self):
    return f"{self.title}"

class Meta:
    verbose_name = 'Группа'
    verbose_name_plural = 'Группы'

class ClassModel(models.Model):  # Занятие
groups = models.ForeignKey(GroupModel, verbose_name='Группа', on_delete=models.CASCADE, related_name='classes', default=None, null=True)
classroom = models.ForeignKey('Classroom', on_delete=models.CASCADE, default=None, related_name='classroom', null=True)
date = models.DateTimeField(null=True, verbose_name='Дата проведения занятия',)
theme = models.CharField(max_length=250, verbose_name='Тема', blank=True)
slug = models.SlugField(max_length=100, db_index=True, default=None, null=True)

def __str__(self):
    return self.theme

class Meta:
    verbose_name = 'Занятие'
    verbose_name_plural = 'Занятия'

forms

from django import forms
from manager_school.models import ClassModel


class ClassModelForm(forms.ModelForm):

    class Meta:
        model = ClassModel
        fields = ('classroom', 'date',)

urls

   path('timetable/', timetable, name='timetable'),
   path('revise_timetable/<int:pk>/', revise_timetable, name='revise_timetable'),
]