M587 S”XY1789" P”Jake78"
It looks like in your command you used curly quotes. Make sure you're using straight quotes in all commands, ie " rather than curly quotes, ie ”. Also, you didn't get an 'ok' after the command, so it didn't go through.
SerialTools works, but is a bit finicky about input; you have to get the command right, without pressing delete or cursor keys. I think it sends each character to the Duet as you type them (raw mode), rather than when you press return. If you navigate away from SerialTools to another application, and then back, in the middle of writing the command, the command won't work. You should get an 'ok' when a command goes through correctly. It's also the only terminal program available on the app store that I've found.
If you're okay with downloading software not on the Apple app store, I've been using CoolTerm from https://freeware.the-meiers.org/. Coolterm works well, though I usually have it set to Options > Terminal > 'Line mode', which sends your command line when you press return rather than character by character, and turn on local echo so it shows the command you have sent.
Ian