[Solved] 'Add topic' button to include a font awesome icon
Please use the following CSS code:
font-family: "Font Awesome 5 Free";
The CSS codes should be added in the "Custom CSS code" textarea, located in the Dashboard > Forums > Settings > Style Tab.
Please don't forget to delete all caches and press Ctrl+F5 (twice) on the frontend before checking to reload the updated CSS file.