Where to find Private Key and Private Key when using Firebase Authentication service?

Question

firebase

I'm just getting into the Google Firebase service.

I am doing user authorization for the site via SMS through Firebase Authentication.
I test getting the token status on JWT, namely https://github.com/firebase/php-jwt .

The token is given to me by the Firebase service when the user logs in to the site. But in order to decode the token using JWT, you need to know the Private Key and Private Key. Where can you get them? I didn't find it in the Firebase console.