Firebase hosting rewrite to function doesn't work with firebase-backend

I try to call the rest api from a single page application. I use the features of firebase hosting rewriting ("https://firebase.google.com/docs/hosting/full-config#rewrite-functions"), it allow to call a firebase function without CORS errors.
When i try to call the firebase function deployed with firebase-backend i have this response:
`Cannot POST /addUserRole/addUserRole`
If i try to call the firebase function with POSTMAN it works.

You can check documentation about firebase hosting rewrite here:
"https://firebase.google.com/docs/hosting/full-config#rewrite-functions"