• From the home screen tap on the account icon in the top right corner.
• Then tap the settings link and go to Account and click the Disable Account option

Note: This will temporarily disable your account and you will not lose any data.  This will hide your account from the other members.  If you wish to delete your account permanently, use the Delete Account option instead in the same Account settings. 

Content creators that have paid subscriptions can not deactivate their account unless they stop all billing for subscriptions.