My wife's computer is crashing all the time. I want to reinstall Windows 10 pro. She has Office home and Student 2019 on the computer but I don't have the Product Key. I do NOT have an MS store account nor do I have an Office account. I installed it locally long time ago. How do I get the Key, or how can I reinstall it?

I still have access to the computer, although it crashes all the time. Is there any way to extract the key, or any other way I can reinstall?
Thanks in advance,
Uri