You can choose your favorite genres to appear in the Genre shortcuts section of the Discover page.
In order to favorite a genre, you can click the star button on a genre page.
You can navigate to your profile (your picture or initials in the top corner)
and select "Your Genres". Click the star to favorite genres or to unfavorite genres that are already selected. Select Save.
You can also click the "Choose your genres" button on the Discover page, open your selected genres, and click the star button at the top right of the genre pages.