Navigate to the Office installation directory (e.g., cd "C:\Program Files\Microsoft Office\Office16" ).
The format always looks like this: XXXXX-XXXXX-XXXXX-XXXXX-XXXXX microsoft excel 2019 mso product key
If you legitimately purchased Excel 2019 (or Office Home & Business 2019), the key is likely in one of these places: Navigate to the Office installation directory (e