Build FirefoxDriver with specified binary: https://remarkablemark.org/blog/2016/06/15/firefox-binary-webdriverjs/

package.json

{
  "scripts": {
    "start": "node webdriverjs-set-binary"
  },
  "dependencies": {
    "selenium-webdriver": "^3.6.0"
  },
  "engines": {
    "node": ">=8",
    "npm": ">=6"
  }
}

webdriverjs-set-binary.js

const { Builder } = require('selenium-webdriver');
const { Options } = require('selenium-webdriver/firefox');

// replace `path/to/binary` with your binary path
const options = new Options().setBinary('path/to/binary');

const driver = new Builder()
  .forBrowser('firefox')
  .setFirefoxOptions(options)
  .build();

driver.sleep(3000);
driver.quit();

not working