You can ask Siri on your MacBook to “set an alarm for 8 AM.” She’ll give you a cute nod and say, “Done,” but she secretly creates it in your iPhone’s Clock app via iCloud sync. So unless your phone is nearby, Siri on your Mac is basically useless here. Classic Siri energy.
Can You Set An Alarm On A Macbook – OAPHT
Also, if you ask her twice, she might get sassy. I once got a “You already have an alarm set, but it’s on the device you’re not holding.” Thanks, Siri. Very helpful.