If you want to install Matlab with a student license you just have to follow the (german) instructions at:

If you have problems understanding the german instructions it basically says:

You will be redirected to the TUHH homepage. Enter your TUHH credentials.
You will be redirected to the Mathworks homepage where you can create a MathWorks account or login if you allready have one
After registration or login you will get to the download page
Start the downloaded installer and select the login with a MathWorks account method during the installation
choose the Academic Student Total Headcount license if needed
follow activation instructions

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