Parse error: syntax error, unexpected 'add_filter' (T_STRING)

Hello!
I tried to add this code

backticks[php]
add_filter(‘wp_nav_menu_items’, ‘wps_add_login_logout_link’, 10, 2);
function wps_add_login_logout_link($items, $args) {
$login = __(‘Sign in’);
$logout = __(‘Sign out’);

//use one of the following methods of identification
$menu_id = ’34’;
$menu_name = ”; //name you gave to the menu
$menu_slug = ”; //slug of the menu, generally menu_name reduced to lowercase

if ( ! is_user_logged_in() )
$link = ‘<a href="’ . esc_url( wp_login_url($redirect) ) . ‘">’ . $login . ‘</a>’;
else
$link = ‘<a href="’ . esc_url( wp_logout_url($redirect) ) . ‘">’ . $logout . ‘</a>’;

if ( ($menu_id) && ($args->menu->term_id == $menu_id) )
$items .= ‘
<li>’. $link .'</li>
’;
elseif ( ($menu_name) && ($args->menu->name == $menu_name) )
$items .= ‘
<li>’. $link .'</li>
’;
elseif ( ($menu_slug) && ($args->menu->slug == $menu_slug) )
$items .= ‘
<li>’. $link .'</li>
’;

return $items;
}
[/php]

to my functions.php file and I received this message

Parse error: syntax error, unexpected ‘add_filter’ (T_STRING) in /home1/wabhh40aayb4/public_html/wp-content/themes/child-theme/functions.php on line 4

and now I’m stuck with that message I can’t do anything.
I deleted the code and left the file looking like that
<?php
/* Write your awesome functions below */
but the message remains.
my website is myecoways.com