IJ Robot not performing [Enter] KeyPress?

[Rocco D'Antuono]

Dear all, I need to call a plugin many times in a macro, passing it different parameters each time.
I wrote a macro that works fine for each single step, but every time the plugin finishes to execute his work, shows a message saying it has completed his duty, blocking macro execution;
so I thought an easy way to bypass this could be use of "IJ Robot" plugin with "KeyPress [Enter]" option, but it seems not working.
Could you please try to see if running the following example lines you get the window closed, or eventually explain me why is not possible?
Thanks,
Rocco

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waitForUser("Hello");
run("IJ Robot", "order=KeyPress keypress=!");
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