Your question is slightly confusing, but I'll do my best.
The T32 (and T20 and T45) flashes incorporate their own auto flash sensor and circuitry. So for any camera - OM or not - you can flip the back panel over to reveal the ASA, distance and f/stop information and slide the switch to one of the auto exposure ranges, or set it to manual and use the guide number scale or a flash meter to set your camera's aperture.
In addition, for those Olympus cameras that offer off-the-film flash metering, you can flip that back panel over to the almost blank side, and rely on the in camera off-the-film flash meter.
All of the OM bodies I use offer off-the-film flash metering - OM2n, OM 20/G, OM2s and OM4T. Same for the OM2 and OM4.
The OM1 does not offer off-the-film flash metering. Nor does the OM1n.
I don't have enough experience with the OM30 or OM40 to answer your question about them.