How do I enable LiveBlogPosting?

Hello,

Thank you for contacting Rank Math and bringing your concern to our attention.

In the Rank Math free version, you may need to add a custom schema using our filter here to add it:
https://rankmath.com/kb/filters-hooks-api-developer/#extend-json-ld-data

Here is an example of liveBlogPosting schema, and here is the LiveBlogPosting page on schema.org

Moreover, you can import the schema easily using the Schema Generator in Rank Math PRO:
https://rankmath.com/kb/schema-templates/#importing-schema-markup

Hope that helps.

Thank you.