So RW Decal will only work with Earth 6.1 or earlier. Although it is still possible to download Earth 6.1, it doesn't seem to work on Windows 10. So how does one create satellite image decals these days?
You should use the Google Maps API build into Train Sim, it is free up to 200 dollars of usage. So unless you build 24/7 you shouldn't run out that quickly. You need to input creditcard details however for it to work. Some accounts on Google don't require it yet, but it could be one day as it is a slow roll-out.