Give them space. Have patience that they will reach out.

Move around

Stop while it's earlier on so you don't look like a idiot

Don't mess with them

Return the favor

Keep bugging them until they answer....
J/k after a few attempts of nothing. I will cease trying

Annoy the shit out of them. Then if they answer ignore them back

Feel sad

Some people are afraid to verbally set boundaries so they take the easy route and just ghost instead. Take the hint and leave them alone.