I've also included a gcode file for a Prusa Mini/Mini+ which has a Pause At Height for letting you put in the magnet. Note: The pause occurs approximately 21 minutes into the print.
CAUTION: I'm not sure if it's an issue with the Prusa Mini's firmware or an Octoprint problem, but the M601 command doesn't work if you print the gcode file from Octoprint to the Mini. It does work though, if you load it onto a USB flash drive and print from there.
FYI, here's some info on the M601 issue: https://forum.prusa3d.com/forum/hardware-firmware-and-software-help/pause-m601-not-working/
2023-08-01: Added a version with a loop hole for attaching to a keychain.
The author remixed this model.
Remixed to include a pocket for a magnet.