@John_T1D If you have an iPhone or one of many Android phones you really don’t need a Dexcom receiver.
For the iPhone just download the Dexcom mobile app from the App Store.
If you are on Android search for the Dexcom G5 mobile app on the Play Store. It will come up if your phone is compatible. If not compatible try the ported Dexcom app referenced in this thread :
Or, better yet, you can look at this as an opportunity to start using xDrip+