How to index and search dynamically generated pages?

Hi, I haven’t posted in the forums before so hope this is the right place. My website makes extensive use of dynamically generated pages, for example
https://darwinholidayapartments.com/property/?pid=6608
https://darwinholidayapartments.com/property-reviews/?pid=6608
https://darwinholidayapartments.com/bookings/book-single/?pid=6608
and so on. The ?pid=nnnn paramater can be any of several hundred values, each one being a different holiday property.

I would really love to be able to offer users of my website a search function, but the standard WP search doesn’t index these dynamic pages and neither do any of the search plugins that I’ve looked at to date. (just as an aside, no XML sitemaps do either).

Is anyone aware of a plugin, hack, or technique that would enable me to either (a) manually code these pages so that the content is searchable (similar to how Google XML sitemap allows me to add them as “additional pages”) or (b) even better, automatically index dynamically generated pages as well as static pages so that the content is searchable?

Any help or advice sincerely appreciated, I’ve been struggling with this for years!
cheers from the deep tropics,
Cathryn, Darwin, Australia.