CocoaPods could not find compatible versions for pod, how can I fix this?

[ayodejimoshood]

[!] CocoaPods could not find compatible versions for pod "React/Core":
In Podfile:
React/Core (from ../node_modules/react-native)

None of your spec sources contain a spec satisfying the dependency: React/Core (from ../node_modules/react-native).

You have either:

• out-of-date source repos which you can update with pod repo update or with pod install --repo-update.
• mistyped the name or version.
• not added the source repo that hosts the Podspec to your Podfile.