With the German menus, it's under "Lernen" and then "Training" which take you to https://www.chess.com/drills
From there, a simple search for "Lucena" (search is at the bottom) brought back multiple results-
auf Deutsch.
/ I think there is no drills/practice page and you have an extra / on the end of the chess.com/drills page.
Today I got an email with an invitation to play the Lucena Position against the chess.com computer. Premium members can try this drill and I did it.
When I log in as a premium member I can't find the way to that drill section. Under "Lernen" (German version; could be "training" or "learning") I have tactics, videos, lectures, etc.
Why do I as a member have to get an email to find that drill feature? When I try to get there via URL https://www.chess.com/drills/practice/ or https://www.chess.com/drills/ I get the famous 404-page.
How do I get to the drill feature?