Hi @husainarif , the error is very common and can occur while connecting OneDrive/SharePoint list to Excel or Power BI.
In Excel, click Data > Get Data > Data Source Settings , click Clear all permissions.
2 On the Data
tab, click Get Data
, choose From Other Sources > From OData Data Feed.
3. Under **1. Location of the data feed** , in the **Link** box, type the website address (URL) for your Project Web App instance, followed by: **/_api/ProjectData/** .
4. When you try to connect your data source, it will allow you to reenter your credential. Select **Organizational account** , choose the site collection under drop-down, **Sign in** > **Connect** .
For reference, please check the following post:
“Access to the resource is forbidden” while connecting Sharepoint to Power BI
Issue with Excel import