I am currently working on something similar, I have field testers for testing our lorawan coverage, so I need to be able use the heatmap using the signal strength values on a map. 

Could you please give me some pointers on how I can achieve this?

I understand the Heatmap widget does not really take gps coordinates, and also how do we maybe incorporate the gps map with the heatmap widget so as to be able to show the heat map on a gps.

Kind regards

Raymond