BlobService.cs

 public async Task<string> UploadCover(IFormFile form)
        {
            BlobContainerClient blobContainerClient = new BlobContainerClient(_config.GetConnectionString("BlobStorage"), "space-cover-images");

            try
            {
                BlobClient blobClient = blobContainerClient.GetBlobClient(form.FileName);
                // add _copy to filename if blob already exists
                while (blobClient.Exists())
                {
                    var splitArray = blobClient.Name.Split('.');
                    var newFileName = splitArray[0] + "_copy." + splitArray[1];
                    blobClient = blobContainerClient.GetBlobClient(newFileName);
                }
                
                // add blob
                using (Stream stream = form.OpenReadStream())
                {
                    await blobClient.UploadAsync(stream);
                }
                return blobClient.Uri.ToString();
            }
            catch(Exception ex)
            {
                throw new Exception(ex.Message);
            }
        }