MungotheSquirrel 5 points 7m ago
Is it a work question? That's what they're posted for. Just text, "hey Jane, this is John from Starbucks. Would you be able to take my shift next Thursday, 9-4? Thanks either way." Or whatever.
Or do you mean to get their number that way to ask them out or whatever? Yeah, don't do that. At the very least, before you consider asking out a coworker, you should have enough of a social relationship that you already have their number or snapshot or whatever. You should be reasonably sure your feelings are reciprocated before trying to date coworkers.