Scratching post i used has M8 threaded rod on one side. This is used to attach to mounting plate that has matching M8 threaded hole in the middle.
In my case, i mounted the plate to plaster board with two anchors and screws. Mounting plate has two 5mm holes for screws.
Mounting plate reaquires supports. I printed it in PLA but I would prefer PETG.
I glued the plug on with construction adhesive.
The scratching post i used:
https://www.superzoo.cz/nahradni-sloupek-se-sroubem-30cm/
The author marked this model as their own original creation.