How to type the head function of the options parameter of the function returned by createRootRouteWithContext

[HcySunYang]

Hi team, I am working on a SSR project, I found that I can't extract the head function outside due to there is no way to type it. I was trying to type it like below:

As you can see, the ts compiler says that Property 'head' does not exist on type. How can I achieve that? thanks