TemplateSyntaxError: Could not parse the remainder: '()' from 'EXTERNAL_RESOURCES.items()'

When i go to the page it raises django.template.exceptions.TemplateSyntaxError: Could not parse the remainder: '()' from 'EXTERNAL_RESOURCES.items()'

But if i try to remove the '()' just {% for name,link in EXTERNAL_RESOURCES.items %} there is nothing on the page (it's blank).

In external_resources.html:

{% for name,link in EXTERNAL_RESOURCES.items() %}
    <li><a href="{{ link }}">{{ name }}</a></li>
{% endfor %}

In views.py:

EXTERNAL_RESOURCES= {
    'Wiki': 'https://ru.wikipedia.org/',
    'StackOverflow': 'https://ru.stackoverflow.com/',
    'Stepik': 'https://stepik.org/'
}

def external_resources(request):
    return render(request, 'mainapp/external_resources.html', context=EXTERNAL_RESOURCES)

In urls.py:

urlpatterns = [
    path('ext-resources/', external_resources, name='ext_resources')
]

I am a nube in web so I'm glad to any of your remarks:)