I already tried this. I do not have an eject button, and the disk does not show up on the screen

Restart the laptop with the Super Drive connected and press & hold the Trackpad button (or hold the left mouse button).

Here is another option of using the command line:

https://www.lifewire.com/use-terminal-to-eject-stuck-cd-dvd-2260864

If the Super Drive has a small hole on the front near the slot you can try using a paper clip to stick into the hole to manually eject the disc. I don't know if Apple SuperDrives have this manual eject mechanism.