This plugin is an example of search & replace feature with settings.
It is called "Example of search and replace" in the interface and isn't installed by default in cloud, self-hosted and desktop version of ONLYOFFICE editors.
- Insert into document some text for searching (in the plugin code, they are in an array arrCodes).
- Open the Plugins tab and press "Example of search and replace".
- Enter the text you want to replace each field with and press the "Ok" button.
If you need more information about how to use or write your own plugin, please see this https://api.onlyoffice.com/plugin/basic