321405: Empty client_secret

Twilio returned this error because the Token API request did not include a value for client_secret. You must provide a valid client_secret when your request uses a confidential client that requires client authentication.

• The request omitted the client_secret parameter.
• The request included client_secret with an empty value.
• Your application did not load the client secret from configuration before sending the request.
• A deployment or environment variable issue caused your application to send a blank client_secret.

• Include the client_secret parameter in your Token API request.
• Confirm that your application reads the correct client secret from your secure configuration or secret manager.
• Verify that your request body sends a non-empty value for client_secret.
• If you are using OAuth 2.0 client credentials managed in Twilio, review your client configuration in Twilio IAM and make sure you are using the correct secret.
• Regenerate the client secret if needed, then update your application to use the new value.

• Twilio IAM documentation
• API authentication and security