Rank Math is only compatible with WordPress at the moment, event though you will be able to optimize the blog site, the best that you can do is to ensure that you link out to external resources on the main domain/homepage.
To ensure that the homepage is optimized for your SEO strategy, you will also need to manually modify the meta tags since most of them are not updated:
We might need to take a closer look at the settings. Please edit the first post on this ticket and include your WP logins in the designated Sensitive Data section.
It is completely secure and only our support staff has access to that section. If you want, you can use the below plugin to generate a temporary login URL to your website and share that with us instead: