After discussion at pt:WP:Esplanada/propostas/Wikipedia_Store_(6ago2017), Portuguese Wikipedia users decided to add the URL to the sidebar. Since there is a config for this, please make the appropriate changes to the file "InitialiseSettings.php":
'wmgUseWikimediaShopLink' => [ 'default' => false, 'testwiki' => true, 'test2wiki' => true, 'enwiki' => true, 'ptwiki' => true, // This task ],