Your question doesn't provide a lot of technical info to go with.
Therefore, I will provide an High level answer.
Assuming you are using chrome
as your webpage
. Than is possible to open multiple instances of chrome with a proxy flag --proxy-server="foopy:8080"
.
The same high level solution could be achieved with multiple browsers and libs..
Your experience with javascript might help, you can use puppeter & chrome for exactly that.
const puppeteer = require('puppeteer');
(async () => {
const browser = await puppeteer.launch({
args : [
'--proxy-server="foopy:8080"'
]});
const page = await browser.newPage();
await page.goto('https://example.com');
await page.screenshot({path: 'example.png'});
await browser.close();
})();