You will have to do the below steps to render your new widget template:
1) Add ‘django.forms’ to your INSTALLED_APPS;
2) Add FORM_RENDERER = ‘django.forms.renderers.TemplatesSetting’ to your settings.py.
More details : https://docs.djangoproject.com/en/2.0/ref/forms/renderers/#django.forms.renderers.TemplatesSetting