Uploading files named in Cyrillic into a blob container

Faced with an unexpected problem when uploading a .docx file to a blob container. On the line where I upload the file to the blob container, I get a System.AggregateException. Through trial and error, I found out that it was a reaction to the Cyrillic alphabet in the file name. How can I fix it?

Uploading code:

using Azure.Storage.Blobs;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Configuration;
using Microsoft.AspNetCore.Cors;
using Azure.Storage.Blobs.Models;
using System.IO;
using System;
using System.Threading.Tasks;
using System.Collections.Generic;

namespace DocxSender.API.Controllers
{
    [ApiController]
    [Route("api/upload")]
    public class UploadController : Controller
    {
        private readonly IConfiguration _config;

        public UploadController(IConfiguration config)
        {
            _config = config;
        }

        [HttpPost]
        public async Task<IActionResult> Upload([FromForm] IFormFile file, [FromForm] string userEmail)
        {
            // Get Blob settings
            string containerConnectionString = _config.GetValue<string>("ConnectionString");
            string blobName = _config.GetValue<string>("BlobName");

            // Generate unique File Name for Blob
            string fileName = Guid.NewGuid().ToString();
            string extension = Path.GetExtension(file.FileName);

            BlobServiceClient blobServiceClient = new BlobServiceClient(containerConnectionString);
            BlobContainerClient containerClient = blobServiceClient.GetBlobContainerClient(blobName);
            BlobClient blobClient = containerClient.GetBlobClient(fileName + extension);

            var metadata = new Dictionary<string, string>
            {
                { "Email", userEmail },
                { "UserFileName", file.FileName }
            };

            try
            {
                // Upload the stream to the blob with the metadata
                await blobClient.UploadAsync(file.OpenReadStream(), new BlobUploadOptions()
                {
                    Metadata = metadata
                });

                return Ok();
            }
            catch (Exception ex)
            {
                return StatusCode(500, $"Error uploading file: {ex.Message}");
            }
        }
    }
}

>Solution :

If you read the error message, you will notice that the reason you are getting this error is because one of the metadata (UserFileName) value contains invalid characters.

Metadata name/value which are included in the request headers can only contain ASCII characters.

One possible way of solving this problem is to convert the UserFileName metadata value to a Base64 encoded string and then save it as metadata.