Michelle Obama has added 21 new dates to her sold-out book tour.

Fans of the former first lady will get to see her in Nashville, Tenn.; Atlanta, Austin, Texas;  and six European cities promoting her best-selling memoir, Becoming. Her book has already sold 3 million copies in the U.S. and Canada and is the best-selling book of the year after only four weeks on store shelves, per reports.

In Becoming, Obama opens up about her childhood growing up in Chicago, meeting her husband, Barack Obama, who became the nation’s 44th president, and her time in the White House.

People who want to see Obama can sign up to be placed on the registration on the book’s official website. If chosen, they will receive a message Thursday with a presale code. Tickets for the general public will be available Dec. 15, per AL.com.