iPhone RAW output photos is very dark compared to iOS Camera app output

Question

I use the official api to output the raw file. when I transfer it to my mac, it is very dark. But if I shot with iOS original camera app, it is brighter.

This is how I save the proraw file to photo library

let creationRequest = PHAssetCreationRequest.forAsset()
                        creationRequest.addResource(with: .photo,
                                                    data: photo.compressedData,
                                                    options: nil)
                        
                        // Save the RAW (DNG) file an alternate resource for the Photos asset.
                        let options = PHAssetResourceCreationOptions()
                        ////////options.shouldMoveFile = true
                        creationRequest.addResource(with: .alternatePhoto,
                                                    fileURL: photo.rawFileURL,
                                                    options: options)