Adding the Footnotes icon to the CKEditor toolbar

For better user experiences, the Footnotes module has a CKEditor integration. So users can add footnotes directly from the WYSIWYG with no need to open the source code. All you need is to add the Footnotes icon to the CKEditor toolbar.

On the configuration page of the selected text format at Configuration — Content authoring — Text formats and editors. Drag the Footnotes icon from the Available to the Active toolbar.