The Custom Code block allows you to implement any function you need by writing JavaScript code. The custom code needs to implement an interface. You can find examples here.
Add custom code control to the page
Firstly, find the Custom Code
control in the controls add panel. Then, drag and drop it into a section or container on your page.
Set code script
After you have the custom code compiled, copy the code and paste it in the textbox under Content -> Appearance.
Advanced Settings
Set the Advanced options that are applicable to this control.