About two weeks ago, I submitted my sitemap in webmaster of my site https://example.com. It's successfully index, but there's not any single URL discovered. It shows 0 there now. Three weeks have past, but nothing has changed. I indexed my each post manually.
Google crawls pages on it's own schedule. A new site probably has a lower priority than an already existing site with lots of existing traffic. You might want to simply submit a few individual pages to Google Search Console via Inspect URL.
My experience is that it takes about 7-10 days from submitting them via GSC for them to affect the number of pages Google displays.
Even so, Google will still do what it wants to do, no matter what.
Well Sitemap does help Google for crawling all of your site. However, this case will only worked while your site was
indexed. Do you try to inspect your website by pasting it into Google Search Console under
inspect there. You may check your website status.
inspect information, try this.
If you site was not crawl yet, you may try to re index your page again in Google Search Console, well it takes time for Google to crawl a page.
Hope it helps!