Pages might not be indexed by Google for several reasons: the site is new and hasn’t been crawled yet, the content is not accessible to Google’s bots (due to robots.txt restrictions, noindex tags, or requiring login), the site has low authority or poor internal linking, making it hard for Google to find and index the pages, or there are technical issues like server errors or incorrect redirects. Addressing these issues can help in getting the pages indexed.
Keep in mind that indexing pages can sometimes take a couple of weeks.