[SOLVED] Auth problem with electron twilio webhook

Thanks All, I have solved it. the trick ACCis that though the json above in the auth lines says

    "username": 
    "password":

the values to put after them are not the twilio user name and password password, but the SID and Auth Key.

The correct json is therefore:

{
    "eventName": "Switch1Trip",
    "url": "https://api.twilio.com/2010-04-01/Accounts/MY TWILIO ACCOUNT SID/Messages",
    "requestType": "POST",
    "auth": {
        "username": "MY TWILIO ACCOUNT SID",
        "password": "MY TWILIO AUTH KEY"
    },
    "form": {
        "From" : "TWILIO_PHONE_NUMBER",
        "To" : "MY_PHONE_NUMBER",
        "Body" : "Switch 1 tripped"
    },
    "mydevices": true
}