Following is the procedure to provide access to your excel file present in your OneDrive account in Power BI services:

Step 1:

Set up parameters and connections in Power BI file by following this article.

Step 2: 

In the Power BI services, click on "OneLake data hub" and click on your dataset.

Step 3: 

Go to File on top and click on Settings as shown below:

Step 4: 

Go to the Data source credential under dataset and select edit credential: 

Step 5: 

Select oAuth2 as authentication method and Organizational as privacy level and sign in with your credential to access the Excel file: