django.urls.exceptions.NoReverseMatch: Reverse for 'ajax_source_api' not found.

[sergiscar]

Hi. When I wanna use the ajax_source code it give me the error below : django.urls.exceptions.NoReverseMatch: Reverse for 'ajax_source_api' not found. 'ajax_source_api' is not a valid view function or pattern name.
I call it in tables.py in my app like the example app in the project. I use te urls like in the example app in the project. Please need help.