WooCommerce SMS Notification for Orders|Notify seller for order Update
WooCommerce Order SMS Notification.SMS notification to both buyer and seller after an order is placed in WooCommerce.
https://woosms.in/
It uses your Android phone to send messages, so any charges you have to pay when sending messages normally will apply here too. You have to choose a plan from your network operator that allows you to send messages for free.
