Note that this setup may be a moot point as there are important issues when running RT under WSL. One is the overall low performance compared to a Linux in a Virtual Box setup. Another is repeatable freezes of the VM when the contents of the directory currently open in RT are modified on the host. For these and other reasons the Virtual Box setup turned out to be superior to the WSL.
The credit for WSL setup for graphical apps belongs to https://medium.com/@jeffborch/running-the-scenic-elixir-gui-framework-on-windows-10-using-wsl-f9c01fd276f6.