Is this a powermeter? How do I use it?

hi all, been out of the sport many years so never used much of the new tech. Recently bought a second hand bike, I was told the bike has a powermeter. Is this correct? It looks just like a normal crank

If so how do I use it? I dont have a Garmin headunit, but I do have a Garmin Forerunner watch/strava on my phone, is this enough? Many thanks for all your help!