Usage Metrics Report pull through to excel

Quick check - Before opening in Excel, can you see the metrics or any data in the usage metrics report on the browser?

(I assume you are talking about power bi service ...)

If you see data on the browser and no data in excel, then it is an issue to troubleshoot.

Permissions

If you do NOT see data on the browser usage metrics report, then it may be related to the permissions. check this url:

https://docs.microsoft.com/en-us/power-bi/collaborate-share/service-usage-metrics

say as

Also, read

https://docs.microsoft.com/en-us/power-bi/collaborate-share/service-modern-usage-metrics#analyze-usage-data-in-excel 

https://docs.microsoft.com/en-us/power-bi/admin/service-admin-portal#control-usage-metrics