Call to undefined function _samesite_setcookie()

Hi guys.

I’d like to report some issues:

Szczegó?y b??du
===================
B??d typu E_ERROR zosta? spowodowany w linii 154 pliku /..../wp-content/plugins/samesite/samesite.php. Komunikat b??du: Uncaught Error: Call to undefined function _samesite_setcookie() in /..../wp-content/plugins/samesite/samesite.php:154
Stack trace:
#0 /..../wp-includes/user.php(101): wp_set_auth_cookie(2, false, true)
#1 /..../wp-login.php(1187): wp_signon(Array, true)
#2 {main}
  thrown

I changed the name of the function, but when I logged in, admin bar (on frontpage) doesn’t show up and none of this “SameSite” flag is not set.

Cheers

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