Here are three widely used examples:

https://github.com/SpEcHiDe/YouTubeDLBot (Search for “AnyDLBot” on GitHub – it’s the most forked version)

Manually downloading every video from a long YouTube playlist is a chore. Thankfully, several developers have shared powerful Telegram bots on GitHub that handle this automatically. By sending a single playlist link to these bots, you can receive your media directly in Telegram or save it to your server. Top GitHub Repositories for Playlist Downloaders

https://github.com/PR0FESS0R-99/TG-YouTube-Uploader

Diagram (textual):