Google has updated its Indexing API documentation to add a few things but the largest update talks about how "all submissions through the Indexing API undergo rigorous spam detection." Plus, it says ...

Google tightens Indexing API rules, warning users of spam detection and possible loss of access revocation for abuse. Google is cracking down on Indexing API abuse. Multiple accounts or exceeding ...

Currently, the Indexing API can only be used to crawl pages with either JobPosting or BroadcastEvent embedded in a VideoObject. To request more quota for pages with JobPosting or BroadcastEvent markup ...