If you want to use a custom widget template stored somewhere under your “TEMPLATES” directory of your project then follow these steps:
a) Use the TEMPLATES settings that you have provided in your question
b) Set the FORM_RENDERER as following in the settings.py
FORM_RENDERER = 'django.forms.renderers.TemplatesSetting'
c) Add the app “django.forms” to the ‘INSTALLED_APPS‘ list in settings.py
Also, be sure to assign the correct path of the custom widget template relative to your “TEMPLATES” directory to “template_name” attribute of your custom widget.