am trying to upload to a Cloudinary server directly from my client so i could track the progress of the upload but the problem is that when i trigger the post request it always gets "Access to XMLHttpRequest at 'https://api.cloudinary.com/v1_1/[cloudName]/image/upload' from origin 'http://localhost:4200' has been blocked by CORS policy: Request header field authorization is not allowed by Access-Control-Allow-Headers in preflight response" when i tried the same code in my friend's project it worked fine but for me it doesn't which is weird i didn't know where the problem is coming from my upload function : uploadPhotos() { this.coverPhotoFormData.append("file", this.coverPhotoFile); this.coverPhotoFormData.append("upload_preset",[PresetName]); const req = new HttpRequest('POST', 'https://api.cloudinary.com/v1_1/[CloudName]/image/upload', this.coverPhotoFormData, { reportProgress: true, }); this.http.request(req).subscribe(event => { let total = 0; if (event.type === HttpEventType.UploadProgress) { const percentDone = Math.round(100 * event.loaded / event.total); console.log(percentDone) } else if (event instanceof HttpResponse) { } }); } Continue reading...