CocoaPods could not find compatible versions for pod "RNFBApp code example

Example 1: CocoaPods could not find compatible versions for pod "Firebase/Messaging":

I had the same problem, but I solved it like this

rm Podfile.lock
pod install --repo-update

Example 2: CocoaPods could not find compatible versions for pod "ReactCommon/jscallinvoker"

// replace 

pod 'ReactCommon/jscallinvoker', :path => "../node_modules/react-native/ReactCommon"

//with

pod 'ReactCommon/callinvoker', :path => "../node_modules/react-native/ReactCommon"