procedure TForm1.ButtonLastUpdateClick(Sender: TObject);
var
  ResponseOut: TStringStream;
  httpRequest: TStrings;
begin
  ResponseOut := TStringStream.Create;
  httpRequest := TStringList.Create;
  httpRequest.Text :=
  '<?xml version="1.0" encoding="utf-8"?> ' +
  '<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/"> ' +
  ' <soap:Body> ' +
  '   <LastUpdate xmlns="http://web.cbr.ru/" /> ' +
  ' </soap:Body> '+
  '</soap:Envelope>';
  with IdHTTPLastUpdate do
  begin
    Request.ContentEncoding := 'utf-8';
    Request.ContentType := 'application/xml';
    Request.Accept := 'text/xml';
    Request.ContentLength := length(httpRequest.Text);
    Request.ContentType := 'application/soap/xml; charset=utf-8';
    Post('http://www.cbr.ru/CreditInfoWebServ/CreditOrgInfo.asmx', httpRequest,
      ResponseOut);
  end;
  EditResult.Text := ResponseOut.DataString;
end;

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
   <soap:Body>
      <LastUpdateResponse xmlns="http://web.cbr.ru/">
         <LastUpdateResult>2019-12-16T23:27:10.043</LastUpdateResult>
      </LastUpdateResponse>
   </soap:Body>
</soap:Envelope>

POST http://www.cbr.ru/CreditInfoWebServ/CreditOrgInfo.asmx HTTP/1.1
Accept-Encoding: gzip,deflate
Content-Type: text/xml;charset=UTF-8
SOAPAction: "http://web.cbr.ru/LastUpdate"
Content-Length: 214
Host: www.cbr.ru
Connection: Keep-Alive
User-Agent: Apache-HttpClient/4.1.1 (java 1.5)

with IdHTTPLastUpdate do
  begin
    Post('http://www.cbr.ru/CreditInfoWebServ/CreditOrgInfo.asmx', httpRequest,
      ResponseOut);
    Request.AcceptEncoding := 'gzip, deflate';
    Request.ContentType := 'text/xml;charset=UTF-8';
    HTTPReqRespLastUpdate.SoapAction := 'http://web.cbr.ru/LastUpdate';
    Request.ContentLength := length(httpRequest.Text);
    Request.Host := 'www.cbr.ru';
    Request.Connection := 'Keep-Alive';
    Request.UserAgent := 'Apache-HttpClient/4.1.1 (java 1.5)';
  end;