Help with React Native Push Notification.

I'm creating a ios/android app with react native. But im having trouble integrating push notification (FCM/APNS) using Firebase. The apps were previously built in xcode and kotlin and push notification have been integrated in the previous app. I have to use same configuration in react native for push notification. I need someone who understands the issue and fix it. We can have a zoom call and i can explain the issue.