When you create a Twilio API key, you must select a key type. The Stigg credential works with Main and Standard key types.Here are more details on the different API key types:
Main: This key type gives you the same level of access as using your Account SID and Auth Token in API requests.
Standard: This key type gives you access to all the functionality in Twilio’s APIs except the API key resources and Account resources.
Restricted: This key type is in beta. Stigg hasn’t tested the credential against this key type; if you try it, let us know if you run into any issues.