I misunderstood what you were saying, I wasn’t sure if protect required a UniFi hardware console or could be self hosted like the network application can be. It looks like it does require at least a Cloudkey gen 2 (or the plus which is what they currently sell) or one of their integrated consoles like a UDM.
It’s supported natively in the UI to configure: https://help.ui.com/hc/en-us/articles/26301104828439-Third-Party-Cameras-in-UniFi-Protect
It was added in EA in mid September and should be GA now as far as I know.
I use UniFi Protect and record to my UDM, though you should be able to install it all on your own hardware if you’d prefer. Their cameras are pretty decent but a bit pricy in a lot of cases. Though they do support 3rd party cameras now.
I’ve also heard a lot of good things about frigate, but I’ve not really looked into it since I already have UniFi gear.
I use Backblaze B2 through my Synology NAS to offsite my important data. Most things though I just backup locally and accept the risk of needing to rebuild certain things (like most of my movie/TV media files since I can just re-rip my physical media, and the storage costs are not worth the couple of days of time in that unlikely case).
I really think this is key when thinking about your backup strategy that is specific to self hosting compared to enterprise operations. The costs come out of our pockets with no revenue to back it up. Managing backups for self hosting IMO is just as much about understanding your risk appetite and then choosing a strategy to match that. For example I keep just single copy in B2, since the failure mode I’m looking to protect against is catastrophic failure of my NAS which holds my main backups and media. I then use Proton Drive and OneDrive to backup secrets for my 2FA setups and encryption for my B2 bucket. This isn’t how I would do it at work (we have a fair more robust, but much more expensive setup). But my costs for B2 are around $15/mo which I am fine with. When I tried keeping multiple copies it had grown to over $50/mo before I cared enough to really rethink things (the cost of the hobby I told myself).