Messenger chatbox will appear on the live page only.
Adding Facebook Messenger Live Chat to your Store
Step 1: Open the Library, click on Addons > "Default" and you will see our "Facebook Messenger Live Chat" Add-on.
Step 2: The Facebook Messenger pop-up box will appear on the bottom right of the screen. You can now customize your greeting message & decide if you want it to be displayed automatically.
That's it, now let's see how you can configure your page ID and your domain whitelisting.
Retrieve your Facebook Page ID
Whitelist your Domain
Next, you’ll need to navigate to Setting -> Advanced Messaging on your page. Under "White-listed domains", type in both the HTTP:// and HTTPS:// variants of your domain to ensure it works for 100% of users. Then click the SAVE button.