• Edit your CP77 settings normally before we start.
  
• go to OC folder, then => \Users\(userName)\AppData\Local\CD Projekt Red\Cyberpunk 2077
  
• Find UserSettings.json and open it in any editor.
  
• Find DLSS_D option and set value to true, then save the file
  
• Done
  
• (Optional) after you save the file, open file settings and set "Read only", that will not allow you or game to change that value

P.S: For me instead of increase 1-2 FPS i get reduce of 3-5 FPS on my RTX 3080. I guess it heppend because both Denoisers work at the same time.
1) NVIDIA Real-Time Denoisers (NRD)
2) NVIDIA Ray Reconstruction AI

But, you will get better image quality.
And we should wait untill CDPR and NVIDIA allow us to use it without Path tracing...