Not really recommended to use old APIs, but well it should work like this.
import wixUsers from'wix-users';
$w.onReady(function () {
const currentUser = wixUsers.currentUser;
console.log("Current-User: ", currentUser);
if (currentUser.role === 'SiteAdmin'){
$w('#button161').show();
}
else {
$w('#button161').hide();
}
});
Take a look onto CONSOLE in PREVIEW-MODE, what do you get as OUTPUT ?