Hello, Walid
Thank you for contacting Microsoft's Community.
Based on your inquiry, we understand that you are not able to find your certificate in your Learn account. We will be happy to help you.
To verify your missing certificate, we opened a Private Message where we have requested information related to your Learn account to verify it and properly assist you. You can find the access to the Private Message, on the top right corner of this screen, as shown in the image below.

We are looking forward to your information. Just a heads up, remember to only send your private information through private message, in order to protect your data.
If no response is received within two business days, we will proceed to close and lock this case as well as the Private Message.
Kind regards,