As soon as I received e-mail message from CIBC Mobile and Online Banking with "Subject: Your CIBC Costco credit card gift certificate is ready", I followed instructions in section "Here's how to locate your gift certificate:", but gift certificate was nowhere to be seen in CIBC Banking app.
A couple of days later, however, "Open gift certificate" showed up OK in CIBC Banking app. In future, please ensure that the CIBC Mobile and Online Banking is updated BEFORE such e-mail message notification is sent!