I am trying to migrate my google cloud app from Nodejs to native JavaScript, such that it can be run in the browser. However, I can't seem to find any examples of how to authenticate as a service account in the browser. Authenticating in Nodejs looked like this:

const textToSpeech = require('@google-cloud/text-to-speech');
const {Storage} = require('@google-cloud/storage');

const projectId = 'project'
const keyFilename = 'key.json'

const storage = new Storage({projectId, keyFilename});

const client = new textToSpeech.TextToSpeechClient({projectId, keyFilename});

In all of the searching I've done, I've only ever found solutions that use API keys and Client IDs. Additionally, all of these solutions prompt for a user to login, which is not what I want. I'd like to do exactly what the Nodejs code is doing, but in native browser JavaScript.