I use keepassxc on MacOS, Windows, Linux, along with MiniKeePass on iOS. It's synced through my free Dropbox account. I just make sure to set the preferences so that every change to the key database results in a file save.
...so it's not like this app is unheard of, per this thread's parent comment. Super odd that they didn't include it haha
I was always a bit paranoid about this, even though I did it myself.