Cron jobs are not running


I am having issues where the cron job will not run (according to the admin - basic settings page it last ran 8 days ago)
I am running the latest docker NextCloudPi image on a Pi 4.
I’ve seen in the docs that the ‘www-data’ user needs to execute the cron.php file. I’ve confirmed that it exists in the crontab by opening a shell in the NCP container and when I manually run it, nothing happens.
Besides the alert displayed on the admin-basic settings page, I haven’t noticed any other issues so I’m not sure if this is actually an issue.

Should I be creating the cron job on the actual host’s crontab instead of the container?
I’ve copied my NCP docker configs below for reference.
Here’s where the default cronjob was set up.

XXX:~/MyFiles/docker]$ docker exec -it nextcloudpi bash
root@af950bcffb9e:/# crontab -u www-data -l
*/15 * * * * php -f /var/www/nextcloud/cron.php

Let me know if I should have included any more info!

NextCloud - Self-hosted storage

container_name: nextcloudpi
image: ownyourbits/nextcloudpi-armhf
- t2_proxy # This is for traefik
# - “80:80”
# - “443:443”
- “4444:4443” # for the admin page
- $MAINDIR/nextcloud/data:/data
- $MAINDIR/nextcloud/etc-localtime:/etc/localltime:ro
restart: unless-stopped