Here, it explains how to induct Chat Plus to Shopify.
The installation of Chat Plus (Installation of original JavaScript) can only be done above Minimum Plan, and Shopify can be done from trial. Specification of Shopify could be changed, so please be mindful of that.
Copy the chat window code
(1) Log into Chat Plus and click on the setting button on the upper right of the management page.
(2) Click on [General Setting]>[Chat window] on the left side of the screen.
(3) Copy tags within the red box in the section [Chat window].
Induct to Shopify
(1) Log into Shopify.
(2) Click on [Online store]>[Edit code].
(3) In the section [Layout], click on{/}theme.liquid
(4) Paste the code you copied before the </body> tag.
(5) Click on [Preview] and check to see if the chat is displayed.