Hello yusuf Audu,
If you're unable to activate your Azure Sponsorship credit and are encountering issues such as missing subscription or tenant access, please ensure that you're signing in to the Azure Portal with the same account associated with your Azure Sponsorship. Only the account owner has access to the Sponsorship Portal and can activate the credits.
To activate your Azure account, sign in to the Founders Hub Portal, navigate to the Home page, and click on the "Activate Azure" button under the "Activate your Azure Account" section. Complete the registration process and ensure your Microsoft account is properly linked.
If your Azure account was originally set up by someone else and you're now managing it, and you’re receiving tenant access errors, you may need to submit a support ticket. Please specify that the issue relates to an "entitlement transfer" so it can be addressed accordingly.
Refer to the doc, Azure Activation FAQs | Microsoft Learn
Please reach out to us if you have any other queries.
If the information is helpful, please Accept Answer & Upvote so that it would be helpful to other community members.