Download the latest release of Realm files from here or from Github link and extract the zip.
Navigate to ios/static/ directory
Drag Realm.framework to the File Navigator of your Xcode project. Make sure Copy items if needed is selected and click Finish.
Click on your project in the Xcode File Navigator. Select your app’s target and go to the Build Phases tab. Under Link Binary with Libraries click + and add libc++.tbd.