#1. First, hover on the page that you want to add SEO Title/Description and click on the Gear icon
#2. Next, choose SEO and scroll down to SEO TITLE (OPTIONAL) and SEO DESCRIPTION (OPTIONAL) to add SEO TITLE/ DESCRIPTION
#3. Note
It will take some time for the search engine to update. You can submit the sitemap (if you use Google Search Console, you can update the site map there) or share the page on social (Facebook, Twitter,..) for faster updates.