The V1 documented g-code sender is Repetier-Host with setup documentation here.
The absolutely safest way to “send” g-code is to use an SD card with your display in Marlin mode. In your setup, you need to use the SD slot on the SKR Pro, not the slot on the display. Sending issues using other methods are rare these days.
gSender indicates it supports grbl and grblHAL, but no mention of Marlin, so I don’t think it will work for you.
Lightburn does support Marlin and will work well for your setup for laser work. I use it all the time. I’ve read that the Lightburn team is working on a CNC version of the software, but I don’t believe it has been released yet.
For Fusion 360 CAM, you want to use Don Gamble’s postprocessor. Due to changes in Fusion 360, the postprocessor needed to be updated. You can find the latest version here. From my perspective, Fusion CAM is more capable than Estlcam, but has a substantially steeper learning curve.