Non-Olympus compact flash gun
A simple, small flash gun that has been tested and works perfectly on the Olympus Trip 35 camera.
It connects via the hot shoe and takes 2 AA batteries, which are readily available.
These guns are used but in perfect working order. A small LED illuminates when the gun is charged up. Set the Trip's aperture ring to the appropriate f-number as indicated by the distance scale on the back of the flash gun.
The image shown is of a typical flash gun in this class. The one you'll receive will be similar in size and operation but may be a different brand.