I had an educational license

Hello, I am using rhino for almost 2 years now and I had an educational licence. However, today I updated Rhino 6 to Rhino 6.3 and it again asks licence. I thought ok, finding my license key is enough. Unfortunately, I couldn’t find it in any of my e-mail addresses maybe it was given from my professor but I don’t remember… Can you help me in some way?

Contact sales@mcneel.com for assistance… If you didn’t buy the license yourself and someone handed it to you, it might not be legitimate though… unless the school actually bought licenses and distributed them free to students.

I think it was like that. Thank you.