Thanks for trying to play the game!
You need to open a command prompt inside the game folder and launch the game with the following command:
THEg.exe --rendering-driver opengl3
You can watch a tutorial for that if you don’t know how to do these things, i will however make a shortcut in the game’s folder to launch the game in OpenGL mode to make this easier.
Keep in mind, you may be able to run the game but it won’t be as pretty as the Vulkan version. If you want to play the Vulkan version, you will need to upgrade to a graphics card that supports it. :)