Step 1: Describe your environment
- Operating system: MacOS
- Browser: Safari/Chrome
- Firebase SDK version: 12.5.4
Step 2: Describe the problem:
I have filled config.ts then I did npm run build and firebase emulators:start. The page loaded and I click Request Permission and get next output:

Steps to reproduce:
- git clone https://github.com/firebase/quickstart-js
- cd messaging/
- fill
config.ts
npm run build
firebase emulators:start