After generating meetings in Canvas, you can change the duration for receiving a notification.
Access https://sju.webex.com/
Locate and select the meeting that you would like to receive a notification (see Image 1):
Next, click > Edit within the meeting (yellow circle in Image 2):
Scroll down to locate and select > Advanced Options (yellow circle Image 3):
Scroll down to locate Email Reminder and select when you would like to receive an email reminder (yellow circle Image 4):
Once the time has been adjusted, please scroll down to the bottom of the page to save any changes (yellow circle Image 5):