The editor offers a lot of different useful widgets, which are shown as modules. However, if there is any functionality that one of the existent modules can't perform or you have any widget of your own creation that you wish to add to your website it is possible to do so through the HTML module.
How to add custom widgets?
To add a custom widget to your website you must use the HTML module. Drag the module from the Basic Modules top bar into the website and place it wherever you prefer. You can then write or copy-paste the HTML snippet and when you are done simply click on Save. To learn more about the HTML Module, please click here.