Hi is VAPI able to use AWS Connect for outbound telephony calls, as an alternative to Twilio?

Yes, you can use AWS Connect with VAPI, which will require some of our development time.

Is there a specific API call that we can use for this? Is it considered an SIP integration? Any guidance would be most appreciated! 🙏

yes it is considered SIP integration, https://docs.vapi.ai/advanced/sip/sip-trunk