What does 143 mean from a girl?

Excuse me, I'm curious about a common phrase or number that's been circulating. Could you possibly explain what the significance of "143" is when it comes from a girl? I've noticed it mentioned in a few contexts, but I'm not quite sure what it's supposed to represent. Is it a code for a particular emotion or sentiment? Or perhaps it's a reference to something more cultural or popular? I'd appreciate it if you could shed some light on this matter.