@Deno44 - Here are a few tings to note from the Education Plan help center article FAQ:

10. I have a Miro profile registered under my personal email and would like the Education team to be created in this profile. What do I do?
- Change your profile email to your educational email following this guide and apply for Education plan under your educational email.

11. I have a Miro profile registered under my personal email while Education plan has been created for my educational email. How can I merge my two profiles? 
- You can move your boards from one profile to another using this guide.

If your current scenario aligns with the second one above, i.e., your Miro account profile was set up using your personal/free-mail/non-educational email address, then your current account would not have been upgraded/changed and you would likely have an email in your school inbox with instructions on signing into your new account.