M365 has something similar (ability to share a calendar with another entity (by providing an email address, which presumably triggers an email with a relevant l

M365 has something similar (ability to share a calendar with another entity (by providing an email address, which presumably triggers an email with a relevant link) with some granularity as to what's visible), but I think when I looked at one of these "shared calendar scheduling" options quite some time ago it wasn't looking for a sharing URL but for an OAuth connection (probably to be able to add appointments directly to a calendar). That made me twitchy enough that I bailed on the idea.