Bought something less than an hour ago and I would like to cancel it.

Bought something and now I would like to cancel the order and return it. Is there any way to do that or is it that I have to wait for the package to arrive and then return it. I also thought that considering I’d purchased it in less than 24 hours the option to cancel the order would be available but it seems like it isn’t. I’m pretty sure I can’t cancel it but I wanted to know if there was any way.

Anyone know what to do, anything is appreciated