built-in screen grabber

Hello everyone!

I am experimenting same issue as mentionned, i cannot start the screen grabber (belgian keyboard). I tried to switch my keyboard on english layout, but no clue where is this ~ on qwerty layout, or it didnt work ( i tried with the key on the upper left, just under “esc key” and adding ctrl and shift)

 

So please can someone help me find a solution?