Hello Singh!
Thank you for contacting Microsoft's Community.
Based on your inquiry, we understand you have passed the AZ-400 exam; however, your certificate is not visible on your Profile. We will be happy to help you.
Please bear in mind that the Exam AZ-400: Designing and Implementing Microsoft DevOps Solutions - Certifications | Microsoft Learn is one of the conditions to obtain the Microsoft 365 Certified: Administrator Expert Certification as shown in the image below:

Keep in mind that the AZ-400 Exam does not issue a Certification by itself.
The available requisites for the Microsoft Certified: DevOps Engineer Expert - Certifications | Microsoft Learn, are the following for your reference:
With this information clarified, you should be aware that one of the prerequisites has expired. Keep in mind that certificates do expire and need to be renewed.
For doubt regarding renewals, please refers to: Renew your Microsoft Certification - FAQ | Microsoft Learn. If you still have questions about this, please let us know.
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We would be grateful for your response. In case we do not receive an answer within one business day, the thread will be closed and locked, and you will not be able to reply through either channel.
Kindly,