If you're using the Traeger x MEATER 2-Pack, this won't pair with the MEATER app, but you'll be able to see your meat temperature right on the touchscreen of your Timberline grill. From there, you can monitor both the meat temperature and the grill temperature in the Traeger app.
If that's not what you have, we recommend double-checking your product's manufacturer. Since we've been around, we've seen a few other wireless thermometer companies spring up, even some that design their product to look a lot like ours. If you have one of these competitor thermometers, it won't be able to pair to the MEATER app.