STP is an acronym for Stand to Pee.
There are parts of the population that use devices to funnel our flows from straight down, to inches in front of us. The item being called a Stand to Pee Device.
Models of these prosthetics range from realistic to actual funnel-shaped ones marketed to ciswomen in the camping section.
The act of standing and peeing may be achieved without an STP device through practice. A combination of abdominal tension, force control (like when you ‘super pee’) and angling with your hand or fingers.