What does htx mean in text?

Excuse me, could you please clarify what "htx" stands for when used in text messaging? I've seen it used a few times but I'm not entirely sure of its meaning. Is it an abbreviation for a specific phrase or term? Or perhaps it's a slang word that's commonly used in a particular community or context? I'd really appreciate it if you could shed some light on this for me. Thank you in advance.