This permanently deletes your account and all cloud data (profile, habits, goals, completion history, backups). Data stored locally on your device is kept unless you uninstall the app.
Email chiragkdarji@gmail.com from the Google account email you signed in with, with the subject "Delete my Smart Habit Tracker account". Your account and all associated cloud data will be deleted within 30 days, and you will receive a confirmation reply.
Note: subscriptions are managed by Google Play - cancel any active subscription in the Play Store's Subscriptions section (deleting your account does not cancel a subscription).