If it’s in a Custom Tile with your own HTML + JS, you could use any of the gauge libraries that are available on the web. We put together two Gauge Custom Tile examples that you might find helpful as a reference.
Alternatively, if you can get the Air Quality Index from Purple Air into a SharpTools Variable, you could use the native gauges that we released for Super Tiles. For example, if your Custom Tile is using API calls to get the AQI value, you might be able to mirror that logic in a SharpTools Rule.