Where is the battery located on a gas scooter/?

i can not find the battery on my gas scooter

Under the seat.
Same place as those motorized power wheels.
Which is about the same as what you're riding.

Always give year, make, engine size and model # when asking questions. All bikes are not created equal.
If it's not under the seat -
It could be behind the front panel. Remove the panel below the seat in the front.
Also some scooters have a trap door in front of that panel beneath the floor board.

who knows call your authorized scooter dealer.

under the seat or in the side opposite the motor

All your scooters electrical wires will eventually lead back to the battery, start by looking at the wires that are easy spotted around the headlight then visually trace them back to the battery. usually the battery is near the center of the bike. Some motor bikes and scooters don't have battery's. A lot of the off road "dirt bikes" and a few small road bikes just run off their own magnetos and are kick started.