Cannot download run background in iOS

[ghost]

Hi all, I have an issue on download run background in iOS. I did like document about config for it (add into AppDelegate.h and AppDelegate.m), but it doesn't work (https://github.com/Jacse/rn-fetch-blob#ios-background-uploading)

• "rn-fetch-blob": "^0.10.13"
• "react-native": "0.55.4",
• Xcode Version 10.1 (10B61)

 RNFetchBlob
      .config({
            IOSBackgroundTask: true, 
            IOSDownloadTask: true, 
            overwrite: true,
            path: tmpPath
     })
     .fetch('GET', url, {
        Range: `bytes=${stat.size}-`
     })