auth.js

//Option 1: btoa function
//    This works when the script is running in the browser (i.e. with a button or clicking "run").
//    This will not work for automation, which run on Airtable servers.

btoa(TWILIO_ACCOUNT_SID + ":" + AUTH_TOKEN)

//Example usage:
var myHeaders = new Headers();
myHeaders.append("Content-Type", "application/x-www-form-urlencoded");
myHeaders.append("Authorization", `Basic ${btoa(secrets.Account_SID + ":" + secrets.Auth_Token)}`);


//Option 2: Minified base64 encoding function
//    This works anywhere
//    Copy and paste the below comment and minified function at the top of your script

// The following line is a minified version of https://github.com/mathiasbynens/base64/blob/master/src/base64.js to allow us to base64 encode strings which is required for HTTP Basic Authentication
!function(e){var t="object"==typeof exports&&exports,r="object"==typeof module&&module&&module.exports==t&&module,o="object"==typeof global&&global;o.global!==o&&o.window!==o||(e=o);var a=function(e){this.message=e};(a.prototype=new Error).name="InvalidCharacterError";var n=function(e){throw new a(e)},c="ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/",d=/<%= spaceCharacters %>/g,h={encode:function(e){e=String(e),/[^\0-\xFF]/.test(e)&&n("The string to be encoded contains characters outside of the Latin1 range.");for(var t,r,o,a,d=e.length%3,h="",i=-1,f=e.length-d;++i<f;)t=e.charCodeAt(i)<<16,r=e.charCodeAt(++i)<<8,o=e.charCodeAt(++i),h+=c.charAt((a=t+r+o)>>18&63)+c.charAt(a>>12&63)+c.charAt(a>>6&63)+c.charAt(63&a);return 2==d?(t=e.charCodeAt(i)<<8,r=e.charCodeAt(++i),h+=c.charAt((a=t+r)>>10)+c.charAt(a>>4&63)+c.charAt(a<<2&63)+"="):1==d&&(a=e.charCodeAt(i),h+=c.charAt(a>>2)+c.charAt(a<<4&63)+"=="),h},decode:function(e){var t=(e=String(e).replace(d,"")).length;t%4==0&&(t=(e=e.replace(/==?$/,"")).length),(t%4==1||/[^+a-zA-Z0-9\/]/.test(e))&&n("Invalid character: the string to be decoded is not correctly encoded.");for(var r,o,a=0,h="",i=-1;++i<t;)o=c.indexOf(e.charAt(i)),r=a%4?64*r+o:o,a++%4&&(h+=String.fromCharCode(255&r>>(-2*a&6)));return h},version:"<%= version %>"};if("function"==typeof define&&"object"==typeof define.amd&&define.amd)define(function(){return h});else if(t&&!t.nodeType)if(r)r.exports=h;else for(var i in h)h.hasOwnProperty(i)&&(t[i]=h[i]);else e.base64=h}(this);

base64.encode(TWILIO_ACCOUNT_SID + ":" + AUTH_TOKEN)

//Example usage:
var myHeaders = new Headers();
myHeaders.append("Content-Type", "application/x-www-form-urlencoded");
myHeaders.append("Authorization", `Basic ${base64.encode(secrets.Account_SID + ":" + secrets.Auth_Token)}`);