By default, the platform does not have this option to change the Message icon on your site. You can use the following CSS code.


Please follow the steps below:


1. Go to WordPress Dashboard > Appearance

2. Customize

2. Additional CSS

3. Append the following:


.messages-wrap i.bb-icon-inbox:before {

 content: '\ee62';

}


4. Click on Published to save the changes. 


You may choose the code icons from the link below. 


https://www.buddyboss.com/resources/font-cheatsheet/


Sample screenshot for reference: