MENU MOBILE NOT SHOWING

Good morning,

Visiting my site (https://farmaciacorvigianni.it), i saw that the hamburger menu at the top right of the display not works correctly, not showing the various menu items.
It not works for all mobile devices (iOS, Android, ecc.)

Can someone help me with a solution?
Thank you in advance,

Gabriele

The page I need help with: [log in to see the link]