The Page Properties Report macro appears to use an internal API of the following form to generate reports:

https://tenant.atlassian.net/wiki/rest/masterdetail/1.0/detailssummary/lines?pageSize=30&pageIndex=0&cql=label+%3D+%22foo%22+and+space+%3D+currentSpace+(+)&spaceKey=FOO&contentId=123456789&countComments=false&countLikes=false&sortBy=&reverseSort= 

This is an internal API, yet there has been a request to provide this information through a public API such that it is supported. 

For further context, see https://community.developer.atlassian.com/t/get-page-properties/43848.