If you launch a new website, or just update an existing website, it is important for SEO to submit your sitemap.xml file to Google and Bing. If you have already set it up, it's also good to resubmit your sitemap to Google and Bing when adding new pages or content so they re-crawl the website and index any new pages or blog posts. Here's how:
In Google, go to the Search Console here: www.google.com/webmasters/tools/
(you will need to have a Google account or set one up)
If you have not yet setup a Search Console account for your site, you also will need to add it, and verify your website via inserting the meta tag code into the SEO tab Header code field, found in the Wix Site Manager. Once verified, you can submit your Sitemap in the "Crawl" section of the account's Search Console. See screenshots below:
For Bing, you also will need to submit and resubmit sitemaps via their Webmaster Tools here:
You will also need a Microsoft/Bing account to do this.