Storing reference of the `RCTResponseSenderBlock` react-native IOS, application crashes

Question

I am trying to store the reference of the RCTResponseSenderBlock to use it letter

// declaration

@interface AppDelegate()

  @property (nonatomic, strong) RCTResponseSenderBlock callback;
  
@end

// exporting

@implementation AppDelegate
RCT_EXPORT_MODULE()


RCT_EXPORT_METHOD(callback: (RCTResponseSenderBlock)callback) {
  self.callback = callback;
}

- (void)sedEvent {
  dispatch_async(dispatch_get_main_queue(), ^{
    self.callback(@[@("ScanningComplete")]); // application crash here
  });
}

// implementing delegate

@interface AppDelegate : EXAppDelegateWrapper <RCTBridgeDelegate, RCTBridgeModule>
-(void) sedEvent;
@end

But the application is crashing when self.callback(@[@("ScanningComplete")]); is executed