To update your payment details for any of Sharecare's Behavioral Health programs, please go to https://app.claritasmind.com then choose the correct program and login with your username and password.
From the main menu, click Payment Details to update your current credit card (see screenshot below).
For Apple (iTunes and App Store) subscriptions check this guide: https://support.apple.com/en-us/HT201266
For Google (Play Store) subscriptions check this guide: https://support.google.com/googleplay/answer/4646404?co=GENIE.Platform%3DAndroid&hl=en