Best practice to have gated white paper indexed by Google

[NikCall]

Our main website white paper page has an image and brief description of the white paper.  Once you click the white paper you are redirected to a form to access the gated white paper. Once you complete that form you are redirected to the white paper pdf which is housed on a subdomain/Hubspot.

Because of this, I do not believe our website is getting "credit" for the keywords/content on these pages. Any suggestions on how we can allow the search engines to crawl this content while still keeping it gated? As I understand it a sub domain cannot hep or hurt (aside from critical crawler issues) the main domain.

Thank you

[NikCall]

A similar question- we have informational, content rich brochures in PDF form on Hubspot.  Hubspot does not allow PDFs to be added to the site map. Is there another way to get these indexed and searchable?

[DanKellyCockroach]

I think I have the same question. I was just going to ask it less intelligently. Our gated content always takes the shape of a PDF form on Hubspot.

What are the best practices for getting some SEO benefits from the Case Studies and white papers that we gate?

(In case anyone is interested, here's a landing page where you can see what I mean: https://www.cockroachlabs.com/case-studies/mux/)

Thanks everyone!