Hi Jan,
May I ask where you purchased your license from?
If this is a retail purchase, you can download the ISO from the Microsoft Evaluation Center here: https://www.microsoft.com/en-us/evalcenter/
Then use your product key to activate after installation.
If the license was purchased through Volume Licensing (VLSC), please sign in to the Volume Licensing Service Center to access the download.
If this was helpful, please click "Accept Answer". If you have any further questions, you can leave a comment. I hope this helps and wish you success in resolving your issue. Have a great day!
TV