[Plugin] GPIO Buttons: Control Volumio 2/ Volumio 3 with buttons

Hello to all of you,
New here, I don’t know if I’m posting in the right place, please excuse me…
Moreover English is not my language, I write thanks to Deepl…
I installed VOLUMIO 3 (3.396 and 3.423) on Paspberry pi 3B and 3B+, until now, all is well.
But when I install the GPIO Buttons Plugin (0.8.3) proposed by the download interface, it is impossible for me to turn off the system, whether I choose to connect my pushbutton between the chosen GPIO and the ground or the +3.3, could someone help me,
thank you in advance for your lights…