Where did you do this at? in the game settings on steam
you have to find your base game files, where the game was installed to. Then find the game.xml file. On line 18 is the renderer section. It has this as the line: <renderer>D3D_12</renderer>. Change that to <renderer>D3D_11</renderer>. Save the game, then go. With each game update, that line will change back to the original