You can use the Child theme > customize the Footer > add the embed WhatsApp code into there, it will work.
Or you can refer to this plugin: https://wordpress.org/plugins/wp-whatsapp/ Hope that this will help you
If you are satisfied with this support, hope that you will spend a little time and go to this website:
https://themeforest.net/item/armania-elementor-woocommerce-theme/reviews/26743715 and leave your 5 stars and your good comments there. It is really worth to me
Thank you so much!
Yame