how to get env variable in scss

There is a simple way to do it. Follow steps as below,

Correct me if wrong, you want to pass an URL to main-v2.scss file as a variable.

1. Add a variable in your .env file as below,

   MIX_AWS_URL='https://your-aws-endpoint.xyz?v1'

2. In your webpack.mix.js file, add as below,

       mix.sass('resources/assets/sass/main-v2.scss', 'public/css', {
          // Use "data" for prependData instead of data.
          data: '$awsUrl:\'' + process.env.MIX_AWS_URL + '\';'
          // single quotes needs to be added as your URL contains : (colon) so, it may create an issue. Better to escape.
       })
   

3. Next, you can directly use $awsUrl variable in your main-v2.scss file as below.

       // Pass to function
       @import url($awsUrl);
   
      // Or assign to another variable
      $myVariable : $awsUrl;
   

That's it!

---

Update

For Laravel 8+, use below in step 2,

mix.sass('resources/assets/sass/main-v2.scss', 'public/css', {
   prependData: '$awsUrl:\'' + process.env.MIX_AWS_URL + '\';'
   // single quotes needs to be added as your URL contains : (colon) so, it may create an issue. Better to escape.
})

I only got it working requiring dotenv myself inside webpack.mix.js.

This should work:

let mix = require('laravel-mix');
require('dotenv').config();

mix.sass('resources/assets/sass/main-v2.scss', 'public/css', {
    data: '$awsUrl:\'' + process.env.MIX_AWS_URL + '\';'
})