The Spring Seller Update included a rollout of the new "Store Experience" which creates a mobile friendly store using better SEO practices and secure links.
Search Engine Keywords and HTML Builder are obsolete (SEK hasn't worked for years and the Link builder creates insecure, outdated links)
We will supposedly get new tools "soon"
https://pages.ebay.com/seller-center/seller-updates/2018-spring/ebay-stores.html
penguins_dont_fly is a Volunteer Community Mentor
Buying and Selling since 2013