I’d start by checking whether this issue is isolated to iOS.

First, try running your app in Android Studio.

If it crashes on Android as well, you'll at least have better debugging tools available, like logcat, to help you investigate further.

If it runs fine on Android, the issue is likely iOS-specific. Common culprits include:

• Misconfigured libraries
• Startup-related issues (e.g., splash screen)
• iOS-specific misconfigurations—especially in the ios directory, most often in AppDelegate.h or AppDelegate.mm

Another approach—especially if your project is still relatively small—is to create a fresh React Native project and gradually migrate your code into it in small chunks. This way, you can isolate and identify what exactly is causing the crash.