Why your website is not showing in Google
Before changing anything, find out which of two completely different problems you have: Google does not have your pages, or Google has them and nobody is reaching them.
That question has a free answer, from Google, in about a minute. Almost every guide to this subject skips it and hands you a checklist instead, which is why people spend weeks fixing the wrong thing.
Which stage you are stuck at
Google describes its own work in stages, and says plainly that pages drop out along the way:
Google Search works in three stages, and not all pages make it through each stage
The stages are crawling, then indexing, then serving a result to somebody searching. Each one is a gate, and a page that fails an earlier gate never reaches the later ones, which is why the order is the diagnosis.
Your site is stuck at one of them, and the fix is different for each. Search Console will tell you which, free, for a site you can prove you own: its URL Inspection tool answers whether a given address is in the index, and its pages report says the same thing for the site as a whole.
If your pages are in the index, stop reading about indexing. You have a ranking problem, and it is a different subject with different answers.
A rough version without any account: search for your address with the site: prefix. It is less reliable than Search Console and will not tell you why, but nothing has to be set up first.
How long it takes a new site to show up on Google
Google gives a range for one step of it, on the page about asking it to recrawl:
Crawling can take anywhere from a few days to a few weeks.
That is crawling, the first of the three stages. Indexing and appearing in results come after it, and the same page says a request does not guarantee inclusion at all. So a site that is a week old and not showing up has not failed anything yet.
What shortens the wait is giving Google a way in: a sitemap submitted in Search Console, and at least one link from somewhere Google already visits.
The causes, likeliest first
Ordered by how often each turns out to be the answer, rather than by how serious it sounds. An unordered checklist is the same as no order at all: the reader starts at the top, and the top is usually not their problem.
The site is new, and nothing is wrong
Crawling and indexing are not instant. Google’s own estimate for a crawl is a few days to a few weeks, and it does not promise inclusion even then. If the site went up days ago, the honest answer is to submit the sitemap, check back, and spend the week on something else. This is the most common answer and the one nobody wants.
Nothing links to it and no sitemap tells Google it exists
Google finds pages by following links and by reading sitemaps. A new domain that nothing on the internet points at, with no sitemap submitted, has given Google no way to learn it is there. The fix is dull and it works: submit the sitemap in Search Console.
A noindex left over from building it
A staging flag that never came off, or a content management setting that discourages search engines, will keep a finished site out of the results indefinitely. It is worth ruling out early precisely because it is embarrassing rather than difficult, and the page looks perfect to a visitor.
robots.txt is blocking the crawler
A block left in place from development stops Google fetching the pages. Worth knowing before you act: robots.txt does not remove anything from the results, and adding a noindex while a block is in place cannot work, because the blocked page is never read.
A manual action against the site
Rare for a new or small site, which is why it sits this low, but it is the one cause Google will tell you about directly. A human reviewer at Google has judged pages to break its spam policies, and some or all of the site is withheld from results. The Manual actions report in Search Console shows a green check mark when there is none, so ruling it out takes seconds.
It is indexed, and simply not ranking
This is a completely different problem wearing the same symptom, and it is the reason the order above matters. A page Google has, which nobody reaches, is a question about competition and relevance. Nothing on this list will move it.
The robots.txt case has a trap worth reading before you touch anything, because the obvious fix makes it permanent: indexed, though blocked by robots.txt. If you just want to know whether a noindex on a given page could ever be read, paste your robots.txt into the checker.
If a site has a manual action, some or all of that site will not be shown in Google search results.
Placing the manual action fifth is a judgement. Google publishes no figure for how often it happens.
The sentence the checklists leave out
Every page on this subject implies that doing the things on its list produces a listed website. Google says otherwise, in its own documentation, in one line:
Google doesn’t guarantee that it will crawl, index, or serve your page, even if your page follows the Google Search Essentials.
That is not a reason to do nothing. It is a reason to be suspicious of anybody promising a result, and to prefer the fixes that remove an actual obstacle over the ones that add another tag to a page.
A page selling a checklist cannot afford to quote that sentence. This one is not selling a checklist.
What this product does about it
ShownTrue crawls your site the way a search engine would, records what each page said at the time, and holds that beside the figures Google publishes about your own site. Which is the pairing the question above needs: what you have, and what Google has.
It will not promise to get anything indexed, because nothing can promise that, and the quotation above is why. What it can do is stop the guessing about which stage you are stuck at.
The honest state of it: the crawler works and has crawled this site over the real internet. The Search Console side is written and has never run against a real Google account, so no figure has ever been imported. No customer has run any of it, and there are no results on this page about anybody’s site.