what the body message of the response?
HTTP code is only half the information.
You should get a JSON body which describes the error
This is the wrong token type.
You have generated a “server token” which doesn’t represent a user.
Then tried to perform a task on behalf of a user.
You need a user token
From - Reference | Twitch Developers
### Authorization
Requires a user access token that includes the **channel:manage:raids** scope. The ID in the `from_broadcaster_id` query parameter must match the user ID in the OAuth token.