Navigate to Sites in the left menu, and then click on Chat Widget along the top. Follow the video on what all the customization options are and adjust these settings to your liking.
If you are using built in funnels or websites, you can toggle the widget on in the funnel or website settings. If your website is on another platform, you can click Get Code, copy the code, and install this in the Body or Footer section of your website. Optionally you can send this code to your web developer if you have one and ask them to install in the Body or Footer of the website.