Task: Make a call with Plivo

n8n workflow JSON:
{"name":"","nodes":[{"name":"On clicking 'execute'","type":"n8n-nodes-base.manualTrigger","position":[250,300],"parameters":{},"typeVersion":1},{"name":"Plivo","type":"n8n-nodes-base.plivo","position":[500,300],"parameters":{"to":"+14156667778","from":"+14156667777","resource":"call","answer_url":"https://s3.amazonaws.com/static.plivo.com/answer.xml","answer_method":"GET"},"credentials":{"plivoApi":""},"typeVersion":1}],"active":false,"settings":{},"connections":{"On clicking 'execute'":{"main":[[{"node":"Plivo","type":"main","index":0}]]}}}