This is the documentation for ConfiForms Server/Data Center appHowever, this might also work for ConfiForms cloud and in most cases it does. But please see this page to understand the differences between server and cloud versions of the ConfiForms app.
Generally available for ConfiForms form administrators with Confluence admin permissions and for users who are Confluence space admins of the space where this form is located
Direct URL for Cleanup API is: http://confluence_server/confluence/confiforms/cleanup.action?pageId=PAGE_ID
PAGE_ID is the id of the page where ConfiForms form is configured
You can use it to cleanup data stored by ConfiForms plugin, all data or filtered by filter criteria
Same format as for filters is used: ConfiForms Filters
If your confluence server runs in a root context ("/") then the URL will not include /confluence