Use Toggle Text, not Icon

You can use CSS to override the icon and add text. Sorry, but I can not write CSS for you.

Ahh.. no problem.

Can you tell the what the hook(s) and file(s) that responsible for the icon?

CSS only override is a bad idea.

Please navigate to the Table of Contents Settings admin page and find the CSS option in the Advanced settings section. Enable the CSS option and save the change. That will exclude the CSS which includes the icon.

Here’s a to the code specifically that enqueues the CSS and the icon.

• https://github.com/shazahm1/Easy-Table-of-Contents/blob/2.0.11/easy-table-of-contents.php#L223-L224