To turn To turn off case lighting go to the Microsoft Store, search for and install OMEN Gaming Hub.
There's no need for any of the secondary installs that it tries to trigger - i.e. Light Studio and HP System Event Utility.
Open OMEN Gaming Hub - ignore any attempt to make you sign-in or register for an account.
Ignore Light Studio, click OMEN Desktop and select the Lighting tab.
Then just select each Zone in turn, set its Mode to OFF and click Apply for each.
Note: various older webpages refer to OMEN Control - it's clearly much older, I installed it and it ran but it couldn't turn off the lighting.
Turning off the backlit GEFORCE RTX text on the graphics card seems to be impossible.
For pre-RTX cards there was a tool from Nvidia called LED Visualizer but they provide no such tool for RTX cards:
Many people seem to have tried EVGA's X1. Perhaps it works on EVGA's cards but the general feedback is that it doesn't solve the issue for most people.
Normally, you can determine the cards manufacturer using something like dxdiag but the Omen card is an HP OEM card and the manufacturer just shows up as Nvidia.
If you look at the card itself, you can see its HP PN is L34259-001 which you can google and find e.g.:
https://www.techpowerup.com/gpu-specs/hp-rtx-2060-oem.b8144
Many people seem to be trying to disable its lighting, there are many suggestions that get people nowhere. As of May 2021, the best answer so far is to use black duct tape to cover it up.
From 2 years later, discussing the Omen 45L, your above assessment "Turning off the backlit GEFORCE RTX text on the graphics card seems to be impossible." looks to be STILL the truth. And this is one of the few places on the Internet I could find that sort of definitive statement, so I appreciate it. Now, I needs someone on the Internet to scream WHYYYYYYYYYY?