It says that One-4-All* stuff is polyurethane, which should be safe to laser. I would still want to look at a MSDS first to be sure it is chlorine-free and, has no other corrosive combustion products.
Heat-transfer vinyl is probably not what one wants for making stickers. The polyester film I mentioned will be better for stickers.
There are a couple well-tested options for heat-transfer “vinyl”: LaserFlex and Siser EasyWeed. More here:
*Wondering if they have another product called All-Might.