It won't let me download a song license

Hello! I downloaded a song and a copyright notice popped up on YouTube. When I went to the “My downloads” page to download the license to upload it to YouTube, I couldn’t do it. I don’t even get the song in “My downloads”. I have downloaded it a few times, but the license still does not appear. This is the URL of the song: Descargar Tutorial Música libre de derechos de autor

Thank you and I wait for the answer!