Custom JS libraries in Retool Mobile

I tried to use custom JS library howler.js ( to play sounds in retool mobile.

Code to play audio in query:

var sound = new Howl({
  src: [''],
  html5: true

It works fine in the editor as well as in the preview.

When I run it in the retool mobile app on iOS, error shown is "Can't find variable: Howl"

Do custom libraries not work in retool mobile (yet)?

We do support custom libraries, but Retool Mobile isn't a browser so the howler library will not work. (There is no Web Audio API.)

Custom sounds are on our roadmap, but in the meantime can you describe your use case?

Thank you, I did not know that howler also uses web audio api.

We are building an app for operators in our warehouse and would like an audio-feedback of the quantity of items confirmed by the operator to minimize input errors.

Text-to-speech would be ideal for our use-case, but we could work with pre-fabricated sounds as well.