Go to https://map.purpleair.com and find your location on the map. Choose a nearby sensor by clicking on it and then use your mouse to hover over the ‘Get this Widget’ text. The tooltip will show the sensor id in the id.
I’m surprised you’re getting a sensor on the other side of the world. I haven’t seen that yet. I wonder if the Purple Air API I’m using to find nearby sensors isn’t returning the correct data, or if I have a bug in the app?