Adding / using "External tool" menu option - in PyCharm IDE

I have managed to partially add “QtDesigner” .
Now I am trying to edit that addition.
No matter what click I use to reopen the “add external tool” I cannot open it.
( it shows QtDesigner is installed)

What am I missing ?

( I did post similar in PyCharm “forum” so far no response)

This is not a PyCharm forum. If no answer here, try Stackoverflow.

(Please don’t send people to Stack Overflow for something like this - as it stands, a question like this won’t come even close to meeting standards.)