MP3 downloader

Usage:
Send or forward a text message containing links and I will:
• In Download mode: download every link I support (or use /dl <links>)
• In Links mode: show direct download URLs for every link (or use /link <links>)
• In Ask mode: scan for supported links and ask you to choose download or links
• Use /settings to select working mode for messages without command.
• Use /settings to toggle Captions.
• Privacy mode (https://core.telegram.org/bots#privacy-mode) is disabled, so I scan every group message.
• Supported links and resources:
SoundCloud: tracks/playlists/pages with private widgets
Bandcamp: tracks/albums/custom links
YouTube: videos/playlists/not lives
Yandex.Music: tracks/albums
Mixcloud, Vimeo and almost everything from this list (https://ytdl-org.github.io/youtube-dl/supportedsites.html), but no VK music

Example message:
Hey, check this out! https://m.soundcloud.com/dabilliondollarbaby/rockstar-feat-roddy-ricch and also https://m.soundcloud.com/scumgang6ix9ine/gooba-6ix9ine and youtu.be/Mdzy5RKn434