Yes, the GetPlayerController would be the correct node to use in this case. If you used “Create Widget” on begin play you could use “SwitchHasAuthority” and run remote into the widget and bypass the create widget node with the server pin and continue execution on the other side of the add to view port it if you couldn’t find any other way to implement it. But I wouldn’t personally run any of this on a server event.
Also you can use “GetPlayerController” on the Set Input Mode UI Only node in lieu of the player controller reference you created on your player controller cast.
Make sure that the player controller cast node is the player controller specified in the game mode as well.
If I were to personally do this widget in the player character I would set all this up in the game instance and on begin play cast to the game instance and call that function but use SwitchHasAuthority to only execute on the client with the remote and go around with the server pin to avoid the errors…