Request ppto

Can I request ppto even though I don't have enough but by the time the date rolls around I will? Like I have 6. Something hours and I need to request off May 7th. I know I need to request off now but I don't have enough ppto quite yet. But I'll have 8 hours by that date from working.

Adding that I don't have any PTO. I'm part time and have only been working at Walmart for 3 months. Not sure when it starts accumulating, but I don't have any.