Hi Syed,
Thank you for contacting the Microsoft Community.
I understand you want to know where you can get the exam number for your scheduled retake exam. Allow me to provide you with more information in order to answer your question.
Upon checking, you will receive an exam email confirmation once you have completed the exam registration, that includes the registration ID or exam number. If in any case that you didn't receive an exam confirmation, please try to check your junk or spam as it may have landed on those files. Moreover, if you aren't able to locate the confirmation email, it would be best to contact your exam delivery provider as they are the ones who can resend your exam confirmation.
You can find your exam delivery provider support contact below, depending in your region:
Pearson Vue Support: https://home.pearsonvue.com/microsoft/contact
Certiport Support: https://certiport.pearsonvue.com/Support.aspx
Should you have any questions regarding Microsoft Certification profile access/benefits and exam registration in the future, please don’t hesitate to reach out to us by posting a new question.
If this solves your problem, please indicate “Yes” to the question and the thread will automatically be closed and locked. In case we do not receive a response, the thread will be closed and locked after one business day. Please be advised that after the case is locked, we will no longer be able to respond. If the resolution provided did not resolve the issue, please post a new question.
Best regards,