KPIs and Key Results can be created based on values from Excel, but first a Connector needs to be be created for each Excel document you want to retrieve data from.
Then click Connect A Sheet in the top right
You will then step through the authorisation with Microsoft 365, selecting the Excel document to use and setting the name of the Connector.
The permissions requested are limited to access the content of a specified document and you could get 2 or more approval steps depending on your signed in status
You then pick the Sheet document to use
And finally name it
It will then appear in the list of connected sheets
You can now create the KPI or Key Result
Creating a KPI from Google Sheet & Excel data
Creating Key Results based on Google Sheets & Excel