Right now none of the native clients support SSO. It is a frequently requested feature but, unfortunately, it doesn’t look like it will be implemented any time soon. As with many OSS projects it is probably a case of “you want it, you build it” - but nobody has actually stepped up.
For web access, stick it behind a reverse proxy and use something like Authentik/Authelia/SSO provider of your choice to secure it.
For full access including native clients, set up a VPN.
Immich has completely replaced Google Photos for me, love it!
My only bugbear is that it is updated very frequently (what a nice problem to have!) which in my case requires a manual once-over of my docker-compose file every time in case there are breaking changes.
This might not actually be the first one, but one of the earliest games I definitely remember actually buying with my own money was Geoff Crammond’s Grand Prix 2. I would have been around 7 or so.
Definitely worth it, great game and the demos on the CD introduced me to Transport Tycoon, and the XCom and Worms franchises - and things kind of snowballed from there!