I have installed the module in opencart 1.5.6.4, and there is no links shown for the product share from mobile. But is shown as below. 

<b>Notice</b>: Undefined variable: language_id in <b>var://catalog_view_theme_default_template_module_whatsapp_tpl</b> on line <b>3</b><b>Notice</b>: Undefined index:  in <b>var://catalog_view_theme_default_template_module_whatsapp_tpl</b> on line <b>3</b>

showing like this in whatsapp not getting any link of website...

Help me solve this. Where to find the route file..