Help adding an Action in CiviRules
There is documentation on how to add your own action here: https://docs.civicrm.org/civirules/en/latest/create-your-own-action/.

I would recommend reading the documentation, it will give you a better understanding of what is required. And then copy and adapt as much as you like :-)

If you do not see it in the list of actions it is because you have copied the class, but not added a record to the civirule_action table (from what you describe).