This is a good question. I also can't find the option anywhere. Messages still seem to be synchronized and all, so I wonder if they just forgot to put it in.
I have it now. I was having problem with the Apple ID and keychain like many other people. Once I got that to go away it reappeared.
[automerge]1570614481[/automerge]
This is a good question. I also can't find the option anywhere. Messages still seem to be synchronized and all, so I wonder if they just forgot to put it in.