How to use ngrok with Laravel Breeze (Inertia + Vue.js) when using two different ports?

I am working on a Laravel(v9) Breeze project using Inertia.js and Vue.js. My project runs on two different ports:

Laravel backend (php artisan serve) → http://localhost:8000
Vue.js frontend (npm run dev) → http://localhost:5173

I want to use ngrok to make both backend and frontend accessible publicly. However, since the free version of ngrok only allows one session at a time, I tried defining multiple tunnels in ngrok.yml and running ngrok start –all, but I got the following error:

ERROR: Error reading configuration file 'C:UsersMyUserAppDataLocal/ngrok/ngrok.yml': YAML parsing error: yaml: line 5: did not find expected key

Here’s my ngrok.yml configuration:

version: "3"
authtoken: NGROK_AUTH_TOKEN

tunnels:
  backend:
    proto: http
    addr: 8000
  frontend:
    proto: http
    addr: 5173

Any guidance would be greatly appreciated. Thanks!