The collapsible section has a button in its header, that opens and closes the section.
The default sign in the button is + (plus) or - (minus). But if you wish to use a glyph icon instead you can do the following:
1- Choose a glype icon you want to use.
2- Select the “collapsible section” on canvas.
3- Remove the + sign from the Expand label and - sign from the Collapse label.
4- Set the glyph icon for the expand button (which will show when the section is closed).
- Go to the ‘Properties Panel’> ‘Element’ tab > ‘Style’ option
- Choose the “Button expand” in the Apply style to” dropdown.
- Open the “CSS Name” category and paste the glyph icon code (for example: glyphicon glyphicon-chevron-right).
5- Set the glyph icon for the collapse button (which will show when the section is open).
- Go to the ‘Properties Panel’> ‘Element’ tab > ‘Style’ option
- Choose the “Button collapse” in the Apply style to” dropdown.
- Open the “CSS Name” category and paste the glyph icon code (for example: glyphicon glyphicon-chevron-down).
6- You can now test the form by publishing it, opening and closing the section.