Hi,
As LimeEugenia pointed out, this error could be related to a wrong set of oauth tokens being used when signing the request. Please, can you check if:
- You’re are signing the request with your app consumer key and secret AND your access token key and secret.
- You’re using the correct pair of access token key and secret if you’re connecting on behalf of a user of your app. The access token obtained via Sign in with Twitter only works with the app authorized by the user previously.