Make sure that you have the request context processor included in the TEMPLATES['OPTIONS']['context_processors'] setting, as follows:

# myproject/settings/_base.py
TEMPLATES = [
    {
        "BACKEND": "django.template.backends.django.DjangoTemplates",
        "DIRS": [os.path.join(BASE_DIR, "myproject", "templates")],
        "APP_DIRS": True,
        "OPTIONS": {
            "context_processors": [
                "django.template.context_processors.debug",
                "django.template.context_processors.request",
                "django.contrib.auth.context_processors.auth",
                "django.contrib.messages.context_processors.messages",
                "django.template.context_processors.media",
                "django.template.context_processors.static",
                "sekizai.context_processors.sekizai",
            ]
        },
    }
]

You should also create the core app, if you haven't done so already, and place it under INSTALLED_APPS in the settings:

INSTALLED_APPS = [
    # …
    "myproject.apps.core",
    # …
]