Hi haddyyeung,
Thank you for contacting Microsoft Certification Online Support, I am glad to assist you,
I understand that, you unable to view your schedule exam appointment .
We suggest you may try to clear cache, and use IE inPrivate browser and try to access your Learning dashboard again.
If the issue still persist, please provide us your personal information for further investigation.
To proceed, please respond to the private message I have initiated asking for your account information to locate and verify your profile. To view your private message, refer to the screenshot below:

Please feel free to contact us should you require further assistance.
Thank you for your continued support towards Microsoft products and services.
Best regards,
Carina
Microsoft Certification Online Support
Working: 09:00-18:00 / Monday to Friday (Except Public Holiday)
If this resolves your issue, please indicate "Yes" confirmation and then close the case