Remotely log into computer's GUI

I plan to use Sunshine and Moonlight to remotely turn on my computer and play games, and shut it off afterwards. However, as far as I’m aware, apps don’t launch until I’m logged in, so if I wake-on-lan I would have to log into the GUI in order for Sunshine to boot. I’ve considered using ssh x11 forwarding, but for some reason my password isn’t being accepted so I’ve given up on that.
OS: Manjaro Linux x86_64
Kernel: 6.5.3-1-MANJARO
DE: Plasma 5.27.8
CPU: 12th Gen Intel i7-12700K (20) @ 4.900GHz
GPU: AMD ATI Radeon RX 7900 XT/7900 XTX

the only easy way is probably setting the DE to auto login.

vnc over ssh is likely what you are looking for.