[FIXED]Can't edit a string for "Has Launch Option"

I’m trying to check if a launch parameter is set when opening my game. I use my own game launcher and I do not want the player to open the game without launching the launcher.
Here is the structure of my blueprint:

But I can’t edit “Option to check” in “Has Launch Option”.
I would like to edit the string.

Can you help me please ?

Fixed with this: https://answers.unrealengine.com/questions/933373/cant-edit-a-string-for-has-launch-option.html