[Answered ]-Django.db.utils.IntegrityError: NOT NULL constraint failed: Eid_Post_name.massenger_name

You are trying to create a Name row without a messager_name which is a required field by default when using CharField. You need to make this field nullable:

massenger_name = models.CharField(max_length=50, null=True)

You need to makemigrations and migrate to apply your changes. This will allow you to have a Name row without a messager_name.

Please do not use .get(…) ^[Django-doc], it silences an error when the key is missing, which is the case here.

You should check what method is used and in case of a POST request, handle it properly:

from django.shortcuts import redirect
from .models import Name
# Create your views here.

def Home(request):
    if request.method == 'POST':
        Name.objects.create(massenger_name=request.POST['user_name'])
        return redirect(Home)
    return render(request , 'index.html')

In the model, it makes more sense to use auto_now_add=True ^[Django-doc] for the action_time:

class Name(models.Model):
    massenger_name = models.CharField(max_length=50)
    action_time = models.DateTimeField(auto_now_add=True)
    # …

Note: In case of a successful POST request, you should make a redirect
^[Django-doc]
to implement the Post/Redirect/Get pattern ^[wiki].
This avoids that you make the same POST request when the user refreshes the
browser.

Note: Functions are normally written in snake_case, not PascalCase, therefore it is
advisable to rename your function to home, not Home.