This plugin shows how to search and replace in document on start.
It is without interface plugin and isn't installed by default in cloud, self-hosted and desktop version of ONLYOFFICE editors.
- Enter any text into document (for this example is "ONLYOFFICE").
- In plugin code in "replaceString" field enter text to replace.
- Reopen a document.
If you need more information about how to use or write your own plugin, please see this https://api.onlyoffice.com/plugin/basic