Rocket.Chat has a live chat feature that allows you to embed a chat widget into your website.

Head over to Rocket.Chat app's Administration view, select the Livechat section and enable it. After this, you will find a Livechat entry in the side bar.

You will also find options to customize the live chat widget appearance to match your look and feel there.

Then, copy the Javascript code snippet shown in the Livechat Installation view and paste it to the bottom of your website's html code as the last thing before the </body> tag.

You will now see the live chat widget on the bottom right of your page.