Hi anand,
Thank you for contacting the Microsoft Community.
I completely understand how important it is to schedule your AZ-900 exam as soon as possible as your voucher is about to expire. You’ve earned this opportunity, and I want to ensure you’re supported every step of the way.
If you are using a voucher from the AI Skills Fest Event, please note that according to the event details all sweepstakes vouchers are valid only until June 21, 2025. This means your exam must be scheduled and taken by that date. Unfortunately, the expiration date cannot be extended, and vouchers will not be accepted for exams scheduled after June 21, 2025. For further assistance with your voucher, you may reach out directly with MindHub’s support team at mindhubprohelp@pearson.com. They are equipped to verify your eligibility and explore whether an exception can be made. It’s the most effective way to pursue an extension and make sure your case is properly reviewed.
Since you are trying to take the exam before the voucher expires but currently can’t find any available dates, we recommend contacting your testing center directly for assistance. They may be able to help you secure an earlier slot or make special arrangements, especially if you mention that your voucher is expiring soon.
The testing center also has real-time access to exam schedules and availability, so they’re in the best position to assist you. You can find their contact information at the following link (just be sure to select your region):
Pearson VUE: https://home.pearsonvue.com/microsoft/contact (select your region)
Meanwhile, If the issue persists, please provide the requested information in the private message, along with the recording of the entire process—starting from the troubleshooting until you receive the error.
For Windows devices, use the Snipping Tool to capture the steps: open the tool, select the video icon, click "New," draw the area to record, press "Start" to begin, and "Stop" to end the recording. For Mac devices, please follow the instructions provided in this link.
Furthermore, in case you are interested, I would like to inform you about our current Microsoft Virtual Training Days event. By participating to this event, you can enjoy a 50% discount on the exam fee for selected exams. This is a great chance to advance your career at a reduced cost. Please refer to the image below for more details.

For more information and guidance about the event, feel free to check out the sticky post.
You may also visit the Microsoft Event Catalog and The Official Microsoft Blog to check for any upcoming training and promotions. This way, you will be able to stay up to date on any programs that might be of interest to you.
Let me know if further assistance is needed
I look forward to your response. Please note that if no response is received after two business days, the case will be closed and locked. After the case is locked, we will no longer be able to respond. Thank you.
Best regards,