Have you gone through the registration process? After approval, you should be able to activate Azure student developer pack.
Manoj Kumar - Activate Azure for Students using GitHub Student Developer Pack
https://manojbce.medium.com/activate-azure-for-students-using-github-student-developer-pack-389238de4f8
Additional resources:
- Bimalka Piyaruwan: Upgrading to GitHub Pro and activating the GitHub Student Developer Pack
- GitHub Pack Offer
- GLUGMVIT: Activate Azure for Students using GitHub
- Manoj Kumar: Activate Azure for Students using GitHub Student Developer Pack
- Microsoft Q&A: Azure from GitHub Student Developer Pack
- Stack Overflow: GitHub student developer pack Active Microsoft Azure