What a Discord token is
A token is the key that proves to Discord that you are logged in. Anyone who has it can act as you: read messages, send messages, change settings. It should be treated like a password.
Why tools ask for it
Changing your custom status line automatically means acting as your account from outside the Discord app. Discord’s rules do not allow that kind of automation, so tools that do it can put your account at risk, and a careless tool can leak the token.
The no-token way
Rich Presence is the official channel for apps to show activity on a profile. Statusong uses it to show a card with the song and the live lyric. It talks to the Discord desktop app on your own PC, so it never needs your token or password.
If you still want the status bubble
Statusong can write to the custom status line too. It is off by default, it is clearly labelled as needing a token, and the token stays on your PC. Use it only if you accept that Discord does not officially allow it.
Questions
Should I ever share my Discord token?
Not with anything you do not fully trust. If you do paste one into any tool, change your password afterwards, which also resets the token.
Does Statusong see my token in the default mode?
No. The default activity-card mode never asks for it.