How can I notify Google's search engine of the existence of a website without opening an account with that company?
As explained in Google’s Introduction to Indexing, you don’t have to submit your URLs in order to get them crawled. If you can get links to your new pages from pages already indexed, Google’s crawlers will find the new URLs the next time they crawl the indexed pages again.
There might be an alternative that can be used without Google account: pinging Google with the URL to your sitemap:
Ping Google specifically with the location of the sitemap: (
However, this is documented in a context for notifying Google about changes to your structured data, and it’s not mentioned in the section Make your sitemap available to Google (Submit your sitemap to Google) on a different page, so it’s not clear if Google will accept new sitemaps this way.
A few months ago Google Publish an open submission at Google SERP. You can read for more https://searchengineland.com/submit-urls-google-googles-search-results-272871
And there is some website through them you can submit your site without opening an account.
You can share your content on different Social Media like (G+, FB, Twitter etc.) for quick index your page or website.