Organized from the official: Color correction using Unreal Engine Lookup Table (LUT) | Unreal Engine 5.2 Documentation (unrealengine.com)
1. Screenshot in Unreal Engine
Cut a scene graph in UE4/5 (more representative)
Then, use this image: (don't save this, please click the link to download the original image, the blog will compress it) 
https://docs.unrealengine.com/5.2/Images/designing-visuals-rendering-and-graphics/post-process -effects/look-up-tables/RGBTable16x1.webp
Import the screenshot and this LUT image into PS respectively:
Start adjusting this layer:
For example, modify saturation, brightness, etc.
Drag the adjusted layer directly onto the LUT.
Save, export to UE4/5, use a PostProcessingVolume, turn on ColorGradingLUT, and drag the imported picture to ColorGradingLUT.
After the lens enters and exits the Volume, check the effect:
