How to find all resources loaded not over HTTPS on the website with thousands pages?

I have a site with 10k+ pages. It works over HTTPS But some pages may contain third-party images and javascript loaded over HTTP. A few pages contains also third-party javascript loaded over HTTPS, but that can loads another third-party resources over HTTP.

How can I check all 10k pages regularly and find pages with resourses loaded over HTTP?

I found some SSL checker that can do it (see Other risks of personal data breaches). But it only checks 20 pages.

Is there any solution or script for my 10k pages?