Avoid HTTP call while testing models

I'm writing the unittests for django models, in some of the models i need to make third party HTTP call. Which i do not want to execute while runing the test for example:

def signup_request_post_save_signal(sender, **kwargs):
    if not kwargs.get('created'):
        return
    instance = kwargs.get('instance')
    # make API call

In the test code, using factory-boy module for dummy data to create an instance of SignupRequest.

from factory import django
class SignupRequestFactory(django.DjangoModelFactory):
    class Meta:
        model = User
        django_get_or_create = ('username',)

While saving the instance of the SignupRequest, is there any way to avoid HTTP call in the post save signal?

I have not used this mock/patch, is in this scenario Is mock/patch applicable or not ?