Hi Muhammad,
For WordPress Theme: Just install the “Tawk.to Live Chat” WordPress plugin.
For WHMCS:
1. Open ‘js/main.js’ file.
2. Then search for the comment LIVE CHAT WIDGET
3. Update the widget code with your own widget code.
Please Learn more about Tawk.to Live Chat and Get your own widget code from here: https://www.tawk.to/
Best Regards,
ThemeLooks Support Team