It is indeed an hour meter. The maintenance indicator is the flashing hourglass to the left of the hours.
The hourglass started flashing at 20 hours; that's the first maintenance interval.
I found a YouTube video showing how to do the oil and lower unit fluid changes. The tech connected what appeared to be a maintenance terminal. (I can't find that video again.) The engine computer probably tracks the hours and sets a signal to the hour meter to begin the flashing. I have the Yamaha owner's manual. It does not mention the instruments supplied by Bennington. There is a round Yamaha instrument. There is a sequence on that one to reset the maintenance required message. That instrument has two push buttons.
Are you referring to a Bennington gauge or Yamaha gauge? I have the Yam 6y8 round gauges and can help on that - it's a sequence of holding down a button (mode?) while engine off but ACC on. Get to the maintenance hour selection and reset the hours to zero.
Video below sort of butchers the sequence but gives you the idea. Actual steps are in the Yamaha manual.
If it's a non-Yamaha gauge perhaps reach out to Bennington direct or your dealer.
It's a Bennington gauge. I found the video that you've linked here. There are no buttons on this gauge.
I had a phone call with the service manager at the selling dealer. He doesn't know. They sell many makes and models. He's probably not up to date on every detail. The mechanic who did the oil change is supposed to call me with more information. He's part of a mobile service company that comes to the boat.
I don't have a trailer, so I can't easily take it somewhere. Also, many boat dealers here in FL are not on the water. That's sort of an odd situation. They end up trailering the boat to a launch point.
I would think the gauge is not a Bennington manufactured gauge, but some Faria type that has a Bennington faceplate slapped on it. Maybe check the search function here or try looking on the back of the gauge itself to see what manufacturer is stamped on it.