Google cloud storage signedUrl generating error in NodeJS

[OlammieAO]

I am working in nodejs to upload files(audio/video) and I want to be able to viewed the uploaded file from internet which I have set appropriate permission in the GCP Cloud Storage Bucket. I installed @google-cloud/storage package and upload file, the file i uploaded got uploaded successfully. I actually wanted to get the signedUrl of the uploaded file because I want to keep signedUrl(the public url) so that user can view the file from anywhere some other time.

*******WHAT I WANT TO ACHIEVE

I actually wanted to get the signedUrl of the uploaded file after uploading it because I want to keep signedUrl(the public url) so that user can view the file from anywhere some other time.

*******THE ERROR I GOT

Error: Cannot sign data without client_email. at GoogleAuth.sign (C:\Users\Documents\sample\node_modules\google-auth-library\build\src\auth\googleauth.js:788:19) at process.processTicksAndRejections (node:internal/process/task_queues:95:5) at async sign (C:\Users\Documents\sample\node_modules@google-cloud\storage\build\cjs\src\signer.js:219:35) { name: 'SigningError' }

********WHAT I HAVE TRIED

I have set my command line google application credentials using the following command but no success:

set GOOGLE_APPLICATION_CREDENTIALS='test-project-sa.json'

Below are the code I have tried

npm install @google-cloud/storage

const uploadFile = async (fileToUpload, fileOutputName) =>{

  const projectId = process.env.GCS_PROJECT_ID;
  const keyFileName = process.env.GCS_KEYFILENAME;

   const storage = new Storage({projectId, keyFileName});

  let finalOutputFileName = fileOutputName + Date.now();

  let publicUrl = null;

try{
const bucket = storage.bucket(process.env.GCS_BUCKET_NAME);

  bucket.acl.default.add({
    entity: "allUsers",
    role: storage.acl.READER_ROLE
  }, function (err) {})

  const storagepath = `UserAvatars/${finalOutputFileName}`;

  const fileUploadResult = await bucket.upload(fileToUpload, {
  destination: storagepath, 
  predefinedAcl: 'publicRead', // Set the file to be publicly readable
        /* metadata: {
            contentType: "application/plain", // Adjust the content type as needed
        } */

})

const fileRef = await storage.bucket(process.env.GCS_BUCKET_NAME).file(UserAvatars/${finalOutputFileName});

//This line shows that the file was successfully updated, it logged to console
fileRef.exists().then(function (data) {
console.log("File in database exists ");
});

const response = await fileRef.getSignedUrl({
version: "v4",
action: "write",
expires: Date.now() + 15 * 60 * 1000, // 15 minutes
//contentType: filetype,
extensionHeaders: {
'x-goog-acl': 'public-read'
}
});

publicUrl = response[0];

  console.log(fileUploadResult[0].metadata.mediaLink + "\n \n");

  console.log(`The public url for this file is \n \n ${publicUrl} \n \n`);

return publicUrl;

}catch(error){
console.log(error);
}
}

The file successfully got uploaded to the google cloud bucket but the SignedUrl cannot be generated. I have googled how to solve the client_email ut i couldn't get a comprehensive help.

Please how do i go about this?

Thank you in advance