Axios: https request over a proxy

It's basically the same question here: axios: https request over proxy

I'm using a browser. The following code is compiled by webpack. I tried this :

const axios = require('axios');

var res = await axios.get('https://api.ipify.org?format=json', {
    proxy: {
        host: 'proxy-url',
        port: 80,
        auth: {username: 'my-user', password: 'my-password'}
    }
});
console.log(res.data); // gives my ip and not the proxy's one

I also tried this with the same code, still does not work:

const axios = require('axios-https-proxy-fix');

Then, I tried with httpsAgent :

const axios = require('axios');
const HttpsProxyAgent = require('https-proxy-agent')

var agent = new HttpsProxyAgent('http://my-user:my-pass@proxy-url:port');
var res = await axios.get('https://api.ipify.org?format=json', {
    httpsAgent: agent,
});
console.log(res.data); // gives my ip and not the proxy's one

Is this a bug, am I cursed or maybe do I have a problem reading documentation ?

from Axios: https request over a proxy