Rapid Google Index 9,000 WordPress URLs

I run a WordPress site with roughly 30,000 location-based pages, but only about 1,500 are actually in Google’s index. The site already uses Rank Math for on-page optimisation, yet the “Request Indexing” button in Search Console (10 URLs per day) is far too slow for my needs... (Budget: £250 - £750 GBP, Jobs: Automation, Data Analysis, Digital Marketing, PHP, Python, SEO, Web Scraping, WordPress)