Access to the resource is forbidden. / The credentials provided for the data source are invalid.

Power Query has no valid credentials or permission for the source.

Why it happens

• Expired or invalid stored credentials.
• The wrong authentication kind for the source.
• The account lacks permission on the underlying resource, or a privacy-level conflict.

How to fix it

1. Data source settings > Edit permissions > update or clear and re-enter credentials.
2. Pick the correct auth kind (Organizational account, Key, Basic, Anonymous).
3. Confirm the signing-in account actually has access to the resource.