Get Data - Web Source

Hi sajithgh ,

Try the following steps:

Please first go to Data > Get Data > Data Source Settings > Global permissions > click “Clear Permissions” , this will help to clear existing permissions to prevent the connection remembering any problematic credentials. Then try to connect again via Data > Get Data > From Online Services > From SharePoint Online list.

There are 3 options when you try to connect the site. Anonymous, Windows and Microsoft Account/Organization account. Please make sure you select “Microsoft Account/Organization Account” option > input the related username and password then click “connect”. Please make sure you are signing in with the account that have the permission to access the site. To check this, please use the account to access the list via browser directly, if the account can access this site list, then that means it has the correct permission.

If not work ,you also could try the below:

Step 1: import data source (again) from SharePoint as a SharePoint folder. 

Step 2: go to Advanced Editor and copy data source code. 

Step 3: go to your original table that points to the locally stored data source and replace the data source code with the new code. 

Refer :

https://community.powerbi.com/t5/Desktop/We-couldn-t-authenticate-with-the-credentials-provided-Please/td-p/1062732 

https://community.powerbi.com/t5/Desktop/Issues-connecting-to-sharepoint-credentials-error/m-p/192425 

https://answers.microsoft.com/en-us/msoffice/forum/all/sharepoint-to-excel/028cf722-7d80-4b5a-882c-6345dbbf2c8b 

Wish it is helpful for you!

Best Regards

Lucien