Hi @Shubham Biswas ,
Thank you for posting in this community.
This error typically indicates that the user or application does not have the necessary permissions to perform the requested action.
Here are some steps you can take to resolve this issue:
1.Check Permissions: Ensure that the user or application has the necessary permissions to access the SharePoint site and perform the requested action.
2.Use Correct Credentials: Make sure that the client ID and secret key provided are correct and valid. You can also try regenerating the client ID and secret key and retrying the connection.
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