@ArkIv That’s good.

dotenv not working my quasar. so I mixed your method + qenv.

.quasar.env.json

{
  "development": {
    "ENV_TYPE": "Running Development",
    "ENV_DEV": "Development",
    "API_URL": "https://dev.some.com"
  },
  "production": {
    "ENV_TYPE": "Running Production",
    "ENV_PROD": "Production",
    "API_URL": "https://some.com"
  },
  "test": {
    "ENV_TYPE": "Running Test",
    "ENV_Test": "Test"
  },
  "stage": {
    "ENV_TYPE": "Running Stage",
    "ENV_STAGE": "Stage",
    "API_URL": "https://stg.some.com"
  }
}

quasar.conf.json

const configEnv = require('./.quasar.env.json')

module.exports = configure(function (ctx) {
  return {
    ......
          env: {
             // for settting proxy address with ctx.dev, ctx.prod
             IS_STAGE: false,
          },
    },

    devServer: {
      proxy: {
        // proxy all requests starting with /api to specific url
        '/api': {
          target: ctx.prod ? configEnv["production"].API_URL
          : process.env.IS_STAGE ? configEnv["stage"].API_URL
              : configEnv["development"].API_URL,
          changeOrigin: true,
          pathRewrite: {
            '^/api': ''
          }
        },