This module for ProcessWire implements the website live chat service from tawk.to. Actually the module doesn't have to do much. It just need to inserted a few lines of JavaScript just before the closing body tag on each side. However, the module offers additional options to display the widget only on certain pages.
Visit https://www.tawk.to and create an account. It's free! At some point you will reach a page where you can copy the required JavaScript-code.
Open the module settings and paste the JavaScript-code into the field as shown below. Click "Submit" and that's all.
The settings for this module are located int the menu Modules=>Configure=>LiveChatTawkTo.