Django-admin makemessages does not detect ngettext strings from .html files (write in jinja2), but it is able to detect them in .py files. However, the same command normally detects gettext strings everywhere (including in .html files).

I tried

django-admin makemessages -l en --ignore="*/site-packages/*" --ignore="*/django/*"

and my code in .html is

{{ ngettext( '%(num)d lesson', '%(num)d lessons', 3) | format(num=3) }}