Republish external ical file as Nextcloud calendar?

I have an ical calendar from a service in my homelab which I would like to import and republish as a Nextcloud calendar.

I am aware of the possibility to configure external calendars in the NC calendar app but that is no option for me because every user would have to configure this individually and it would reveal details about the container topology.

I would prefer to import the ical file into Nextcloud centrally because then it would immediately be available for every user of the group it is shared with without those users having to configure anything by hand or getting to know the internals of my homelab topology.

How would I go about to achieve this?