2👍
Try using quotes when using the {% url %}
tag:
<a href="{% url 'admin:pybb_category_add' %}">{% trans "Add a category now" %}</a>%}
...
<a href="{% url 'pybb:mark_all_as_read' %}">
From the docs:
The first argument is a path to a view function in the format
package.package.module.function. It can be a quoted literal or any
other context variable.
Source:stackexchange.com