I have encountered the problem of how to add icons such as emoticons and expressions to the custom menu bar of WeChat official account before, and it is quite easy to solve it. Next, I'll tell you how to operate:

Tools: WIN 10, Little Ant Editor.

Step 1: Search the WeChat public platform and log in the account; Locate the custom menu in the left navigation bar. (as shown in the figure below)

Step 2: Open a webpage to search for emoji expressions, select the expression you want to copy, and then paste it into the background of WeChat official account. (as shown in the figure below)

Step 3: Remember to save and publish after changing the menu bar. (as shown in the figure below)

The above is all the steps to solve how to add emoticons, expressions and other icons to the custom menu bar of WeChat official account. If it's useful to you, remember to like it for me ~