Hi JohnKearns2,
Thank you for reaching out to Microsoft Community.
You may install iTunes on your Surface Pro 5thgen through the Microsoft Store app or through this page: Get iTunes. You may also follow these steps below:
1: Launch a web browser like Microsoft Edge
2: Navigate to iTunes Download
3: Click Download Now
4: Click Save
5: After downloading the file, click Run
6: Click Next
7: Click Install
8: Select Finish
If this answer your question, we highly encourage you to inform our Community by clicking on Yes or marking my post as an answer. This will help other members who may have the same issue as you. Otherwise, don't hesitate to update us so we can further assist you.
Kind Regards,
Marrion Y.