Hi @mhyusi
This is usually quite straightforward to add to a site. Choose your provider - there are many - Intercom, Chatra, and even Facebook Messenger and they will have a section on how to embed the widget in a site. Once installed, you just manage the chat within the provider’s interface.
In Webflow there is a choice to add code to the whole project (dashboard) or at page level (page settings) or within an embed element on the canvas.
Here’s some help if you went the FB messenger route:
You can also use the forum search (top right) if you hit any issues integrating a specific provider’s code.
Hope that helps