Search on specific field is working, search on the page content is less efficient >>> instead use REGEXP
( download the page content: body.storage.value and match with an REG expression , body is part of _expandable)
Regular expression and strip html tag
Advanced Searching using CQL
https://developer.atlassian.com/server/confluence/advanced-searching-using-cql/
...
text~ "bla bla bla" ( include in the content )
https://developer.atlassian.com/server/confluence/cql-field-reference/
