Hi Sumarigo I have share the code, facing some issues can you please review it and confirm? public class CallOutLargFileAzure { public static void largeFileUpload(){ Integer maxBlockSize = 320;//Each file will be split in 256 KB. Integer numberOfBlocks = 1; Integer totalBytesRemaining = 0; String blockIdPrefix = 'block-'; String submitUri = null; Integer bytesUploaded = 0; list ListFile = [SELECT Id, Title, ParentId,ContentSize, FileType FROM ContentDocument]; totalBytesRemaining = ListFile[0].ContentSize; String baseUrl = '"https://tanishka.blob.core.windows.net'; String indexOfQueryStart = baseUrl; submitUri = baseUrl + '/' + ListFile[0].Title;// + baseUrl; String uri = submitUri + '&comp=blocklist';// + 5; String requestBody = ''; for (Integer i = 0; i < 2 ; i++) { requestBody += '' + 'block- i ' + ''; } requestBody += ''; AzureServices.getCustomMetadataValues(); List accessValues = AzureServices.accessToken(); System.debug(AzureServices.accessToken()); Http h = new Http(); HttpRequest request = new HttpRequest(); HttpResponse response = new HttpResponse(); request.setMethod('POST'); request.setEndpoint(uri); request.setbody(requestBody); request.setHeader('Content-Type','application/json'); request.setHeader('Accept','application/json'); request.setHeader('x-ms-blob-content-type',ListFile[0].FileType); request.setHeader('Content-Length','requestBody.length()'); system.debug('#### => '+accessValues[0].token); request.setHeader('Authorization', 'Bearer '+accessValues[0].token); response = h.send(request); system.debug('#### => '+response.getStatusCode()); system.debug('#### => '+response.getBody()); } }