There are a lot of factors that play into whether or not pages are indexed by Google. Their own SEO starter guide has a lot of great tips for how to configure your site and domain for indexing.
There’s not enough info in your post for the rest of us to identify the problem. If you prefer to solve it on your own, the guide above will be helpful. If you want more help from the community, the guide below has some tips on what details you should add here to let us debug together.