Google is not indexing my website.

According to my Google search console after more than a month, Google has discovered 781 pages but it has only indexed 4 of them. My website is: https://www.edward-ardizzone-archive.org/

I'm guessing that you don't actually have 781 pages and most of those are pseudo pages for tags and categories, Google typically won't index these.

Google will also only index pages that it deems to be useful in search results. It's worth making sure that GSC has your sitemap and then go through your most valuable pages and manually request indexing. This isn't guaranteed to work, but it helps tell Google what pages you think are important.

It may be worth you using a service like SEO Space to analyze your website and check that everything is set up as well as it can be.