Crawling and indexing
Whether search engines can find, read and store the pages you want found.
Have you checked in Google Search Console that your main service pages are indexed?
Google says a page must be indexed, and able to show a snippet, to appear as a supporting link in AI Overviews or AI Mode.
Can crawlers reach those pages, with no robots.txt block, noindex tag or login in the way?
A robots.txt block stops Google reading a page, and a noindex tag keeps it out of results, including AI Overviews and AI Mode.
Does every page you want found have a link from at least one other page on your site?
Google finds and understands pages through links, and says every page you care about should be linked from another page on your site.