There many ideas why search engines like Google, Bing, Yandex…etc won’t index your website. The prominent of all reasons is haven’t submited your website’s XML sitemap to the search engine (webmaster) in case of Google you submit to (search console), and you make sure the website’s robot.txt are configured in such a way that allows search engines’ crawlers to crawl the website for optimization. If your website is new, by default the website’s robot.txt is set crawlable needless further configuration.
Even though all said are done, your website may still experience index issues such as "Crawled – Currently Not Indexed”

Which is common index issues in all websites, mostly indicated in your search console or webmaster.
It’s so easy to fix "Crawled – Currently Not Indexed” notice in your search console.
Ignoring this message could negatively affect your website page ranking, affected pages be deindexed for as long as you chose to ignore it.
So, before we fix the error notice, we must first understand what this error means to your website?
“Crawled – Currently Not Indexed” is a search console notice indicating your website page(s) have been accessed by the search engine crawlers (bots) but chosen not to include those web pages on the search results for the targeted keyword.
To understand it further, Search engine has a result page for a searched keyword, website who targeted the keyword with a page indicating "Crawled – Currently Not Indexed”, the page will not show on the search result when someone searches for the keyword. But competitors web pages who were able to do the following SEO practice could show:
Improve affected content: add more information, insights, story-telling and experience than that of the top 3-ranked websites webpages that’d targeted the keyword as you.
Improve interlink structure between content: link content to relevant contents or, if there’s no relevant content, link to relevant tag, category or even homepage.
Remove duplicate content: duplicate comtent are content with same URL slut and same body information. In the case of content with same body information, merge them together, to create long content.
Increase domain & hosting renewal cycle: it has been tested and proven correctly that search engines (like google) are now rewarding old domain websites with top ranking. You may want to extend your website domain registration and hosting renewal cycles upto five years.
Reindex page: Once all said is done, login your google search console or webmaster if other search engines, request for fix or reindex (depends on the language use) of the page or pages with the error.

Most search engines allow bulk fix/reindex of all deindexed pages. Once request for reindex, those page will be on pending.

Within a week, your website quality content will start showing up at index page
Once you’ve followed althrough to this part, you should start seeing some of your pages indexed. More tip to increase your brand awareness across all search engines and, ultimately, the web a whole:
Create Pages & Channels: Create pages on social media and forum platforms and channels on Video streaming platforms like YouTube, Vimeo, Twitch…and start posting various content formats (Text, image with caption, videos and audios) each content should be a link which back your website. Notice which content format work the best for each platform and adjust to it.
Wait: if your website is less than two years old, it is a baby. You have to continue investing quality content before you start seeing positive results. Don’t turn down quick, be committed, because most of the website on top position didn’t start a year ago, rather were more than five years old with non-stop publications (e.g. Quora, Reddit and people)
Follow these steps not only could you index your website pages but also boost your brand awareness for more reach.