I have issue with passing file inside form from Front-End to Backend. My file on backend side is always null. Front-End code:
public getTranslatedJson(
    json: File,
    destinatonLanguage: Language
  ) {
    const form = {
      "languageCharset": destinatonLanguage.systemId,
      "file": json
    }
    return this.http.post(this.url, form, {responseType: "blob", observe: "response"});
  };
Back-End code:
 [HttpPost("")]
    [Route("")]
    public IActionResult Post([FromForm] LanguageCharset languageCharset, [FromForm] IFormFile file)
    {
      var jsonString = new StringBuilder();
      using (var reader = new StreamReader(file.OpenReadStream()) // error here because file was null
      {
       [...]