What do you do when she dose not replay on second message?

Conovo on IG:

Me: I usually don't send messages to girls I don't know, but girls like you are a weakness for me, so ... Hello
She: Hello :D (and likes my photo)
Me: what's up

No answer

What is best message second message in situations like this? I usually send "there is 5 spanks penalty for not answering" and it works in situations where there has been a sexualization of the conversation before that, but it seems to me that this is not a good idea here because it would be an escalation on non-compliance.