#1 - Install via NPM (Recommended):
npm install whatsapp-button.js OR Download plugin files at: whatsappButton.js page and put it inside your node_modules folder.
(path must to be node_modules/whatsapp-button.js)
#2 - Link the .CSS file with a link tag in the head tag of your application;
#3 - Link the .JS file with a script tag in the head or body tags of your application;
#4 - Call your button by inserting the following command in a script tag of .js file: