Use 0.15 layers
Put in a pause at layer 4.25 (insert Magnet)And a Change filament at 9.5 (Color tie)And a Change filament at 9.8 Black
This is the magnet I use.
https://www.amazon.com/gp/product/B01MSTKTSF/?&_encoding=UTF8&tag=10x1309-20&linkCode=ur2&linkId=6e4f1423e7e4a20a78824f5e1053be17&camp=1789&creative=9325
The author hasn't provided the model origin yet.