curl 'https://api.vapi.ai/call' \ -H 'authorization: Bearer TOKEN' \ -H 'content-type: application/json' \ --data-raw '{ "assistantId": "ASSIST_ID", "transport": { "provider": "vapi.websocket" } }' try to do it like this it will work but, unfortunaltey websockets have been crashing since 2 days so waiting for it to be fixed but atleast by making this request you will get wss urls