PedactionNode?
Pedactiontree?
orExecuteactionnode?
You forgot the "Set" in the function names.
PedSetActionTree only works with action trees (fighting styles), not nodes.
PedSetActionNode and ExecuteActionNode is what you are looking for. The difference between them is that with ExecuteActionNode you can't perform a new animation unless you finished the previous one.
Check the lua functions explanations for more info.