Note about react native firebase sdk capitalization issue (#177)

Troubleshooting.md

@@ -54,26 +54,26 @@ there are two possible reasons for this:
 
 ### Deep links in push notifications not getting sent over to React Native layer when the iOS app is terminated
 
-When the iOS app is terminated (killed from the app switcher by swiping up), there is a bug in React Native that 
-prevents the native layer from calling the listeners set up in React Native to listen to incoming deep links. 
-The listener in question here is `Linking.getInitialURL()` which is expected to be called when a deep link is 
+When the iOS app is terminated (killed from the app switcher by swiping up), there is a bug in React Native that
+prevents the native layer from calling the listeners set up in React Native to listen to incoming deep links.
+The listener in question here is `Linking.getInitialURL()` which is expected to be called when a deep link is
 available while the app is terminated.
 
-You can find the open issue describing this problem on React Native's GitHub repository [Here](https://github.com/facebook/react-native/issues/32350). 
-There are many workarounds suggested in this issue's thread and a few other similar issues. 
-However, the workaround that worked for us involves intercepting the launch arguments in the app delegate and adding 
+You can find the open issue describing this problem on React Native's GitHub repository [Here](https://github.com/facebook/react-native/issues/32350).
+There are many workarounds suggested in this issue's thread and a few other similar issues.
+However, the workaround that worked for us involves intercepting the launch arguments in the app delegate and adding
 a key `UIApplicationLaunchOptionsURLKey`, which React Native expects to be present when calling the `Linking.getInitialURL()` listener.
 
 
 Here's a method to implement this workaround:
 
 
-```swift 
+```swift
 - (NSMutableDictionary *)getLaunchOptionsWithURL:(NSDictionary * _Nullable)launchOptions {
   NSMutableDictionary *launchOptionsWithURL = [NSMutableDictionary dictionaryWithDictionary:launchOptions];
   if (launchOptions[UIApplicationLaunchOptionsRemoteNotificationKey]) {
     NSDictionary *remoteNotification = launchOptions[UIApplicationLaunchOptionsRemoteNotificationKey];
-    
+
     if (remoteNotification[@"url"]) {
       NSString *initialURL = remoteNotification[@"url"];
       if (!launchOptions[UIApplicationLaunchOptionsURLKey]) {
@@ -85,7 +85,7 @@ Here's a method to implement this workaround:
 }
 ```
 
-Ensure that this method is called from `application:didFinishLaunchingWithOptions:` before calling the superclass method with the 
+Ensure that this method is called from `application:didFinishLaunchingWithOptions:` before calling the superclass method with the
 modified launch arguments, like so:
 
 
@@ -96,14 +96,19 @@ modified launch arguments, like so:
   self.initialProps = @{};
 
   // some more code ...
-    
+
   NSMutableDictionary * launchOptionsWithURL = [self getLaunchOptionsWithURL:launchOptions];
 
   return [super application:application didFinishLaunchingWithOptions:launchOptionsWithURL];
 }
 
 ```
 
-This implementation is included in the example app in this repo and can be used for testing. 
+This implementation is included in the example app in this repo and can be used for testing.
 Make sure to use the URL scheme (rntest://) of the example app when testing.
 
+### iOS APNS Token Troubleshooting
+There is an open issue with [`@react-native-firebase/messaging`](https://github.com/invertase/react-native-firebase/issues/8022) where the SDK will uppercase any APNS token returned using `messaging().getAPNSToken()`.
+You can verify this by adding a log the `AppDelegate.m` file that prints the deviceToken (you will need to convert to a hex string).
+This might have no impact on your use case, but is something to consider when designing.
+