If you wish to use a file as your data source in Microsoft Power BI, you can easily save that into SharePoint and connect to it from Microsoft Power BI. In this way you will be able to update the file in SharePoint and the changes will be synced with Power BI based on your Refresh settings for this data source.

First, locate the file in SharePoint Online and click on the Details.

On the right side, you will see the file details. Scroll down until you find the Path.

Click on the Copy Direct Link button next to the Path.

Now, go to your Power BI Desktop and select Get Data.

Search for Web.

Paste your direct link.

Login to your SharePoint using your Organisational Account. Now you will be able to use your file as a Power BI data source.