Click Set Reminder after you have written your email and choose when you wish to receive a reminder
Then choose Send Later
Your email will first appear under the Scheduled Mail (1) label of the Wizy.io menu to the left of Gmail. Once the email has been sent it will then move to the Reminders (2) label.
You will receive your reminder email as per instructions given in Set Reminder step
NB: Sending schedule must be EARLIER than the Reminder schedule