​https://angularfirebase.com/lessons/sms-texting-with-twilio/​
// firebase functions:config:set twilio.sid="YOUR_ACCOUNT_SID" twilio.token="YOUR_AUTH_TOKEN"// https://angularfirebase.com/lessons/sms-texting-with-twilio/exports.makePhoneCall = functions.https.onCall((data, context) => {if (!context.auth) {throw new functions.https.HttpsError("failed-precondition","The function must be called " + "while authenticated.");}const twillioPhoneNumber = "+12089532138";const toPhoneNumber = data.phoneNumber;​const accountSid = functions.config().twilio.sid;const authToken = functions.config().twilio.token;const client = new twilio(accountSid, authToken);​const main = async () => {try {const call = await client.calls.create({// method: 'GET',// statusCallback: 'https://www.myapp.com/events',// statusCallbackEvent: ['initiated', 'answered', 'completed'],// statusCallbackMethod: 'POST',// replace with https://www.twilio.com/console/twiml-bins/create,// https://www.twilio.com/docs/voice/make-calls#manage-your-outbound-call// record: true,url: "http://demo.twilio.com/docs/voice.xml",to: toPhoneNumber,from: twillioPhoneNumber});​console.log(call);// should save callSid `call.sid` to firestorereturn {status: "OK",text: `calling ${toPhoneNumber} from ${twillioPhoneNumber}`,callSid: call.sid};} catch (e) {console.error(e);return { status: "error", error: e };}};​return main();});