1 - Go to the Path to game\ThePed_Win_64-Data\managed
2 - Find Assembly-CSharp.DLL and open it in a Hex Editor. I used HxD
3 - Press CTRL+R and click on the Hex-Values tab.
4 - Under Search for type "39 8E E3 3F"
5 - Under Replace for type "26 B4 17 40"
6 - Replace all instances of "39 8E E3 3F" that you can find, replace it 4 times in total.
7 - Save the file.

Originally posted by author:

21:9 (2560x1080)ㅤㅤㅤㅤㅤㅤ26 B4 17 40
21:9 (3440x1440)ㅤㅤㅤㅤㅤㅤ8E E3 18 40
21:9 (3840x1600)ㅤㅤㅤㅤㅤㅤ9A 99 19 40