TPMS ⚠️ light won’t go off

First, does the light come on and stay on as soon as you turn the car on?

Or does it come on blinking, blink for a minute, and then stay on?

If it comes right on and stays on, it is telling you about a tire problem, like low tire pressure.

If it comes on blinking and then stays, it is telling you about a monitoring problem (so, it isn't able to tell you if you have tire problems or not, because of a problem with the monitor system itself).

You can ask it for the trouble code, which will tell you more than just the warning light. If you don't have a scan tool that can read the TPMS codes, you can do this: Blink (a/k/a Flash) Codes – How to. | PriusChat

Depends on what button you mean. There is a TPMS button for setting your preferred tire pressure, which many people mistake for a reset button. What it's for is to change what the car remembers about the tire pressure you prefer. When you use it, the car will remember what the pressure readings are right now from all four transmitters (whether they are right or wrong, good or bad) as being the pressures you want, and give future warnings accordingly.

Doesn't matter how many times you use it; the preferred tire pressures will just be remembered as whatever they were the last time you used it. There's no need to use it if you haven't changed your mind about preferred tire pressures since they were last set. But if anyone has used it at a time when you're not sure all the transmitters were working and all the pressures were right, then once you get everything sorted you should make sure to air all the tires to your preferred pressures and use it again.