I am currently trying to create a mobile application with rewarded ads and I struggle with the code on XCode.

For now I have already integrated interstitial ads and I would like to adapt the code for rewarded ads.

Here is my current working code for interstitial ads adapted from something found on Github:

UIView *gView;
UIViewController *gViewColtroller;

@interface adInterstitial : NSObject
/// The interstitial ad.
@property(nonatomic, strong) GADInterstitial *interstitial;
@property (strong, nonatomic) GADRequest *request;
@end

@implementation adInterstitial

-(id)init {
    [self createAndLoadInterstitial];
    NSLog(@"adInterstitial init");
    return self;
}

- (void)createAndLoadInterstitial {
    self.interstitial = [[GADInterstitial alloc] initWithAdUnitID:@"ca-app-pub-3940256099942544/4411468910"]; // test id
    UIWindow *window = [UIApplication sharedApplication].keyWindow;
    UIViewController *rootViewController = window.rootViewController;
    self.interstitial.delegate = self;

    GADRequest *request = [GADRequest request];
    request.testDevices = @[ kGADSimulatorID, @"2077ef9a63d2b398840261c8221a0c9a" ];
    [self.interstitial loadRequest:request];
    NSLog(@"createAndLoadInterstitial");
}

- (void)interstitialWillDismissScreen:(GADInterstitial *)ad {
    //  Method for reloading the object so that you can show ads again
    NSLog(@"interstitialWillDismissScreen");
    [self createAndLoadInterstitial];
}

- (void)InterstitialView {  // show interstitial ADS
    if (self.interstitial.isReady) {
        NSLog(@"Show interstitial ADS!");
        UIWindow *window = [UIApplication sharedApplication].keyWindow;
        UIViewController *rootViewController = window.rootViewController;
        [self.interstitial presentFromRootViewController:rootViewController];
    } else {
        NSLog(@"interstitial Ad wasn't ready");
    }
}
@end

And here is my attempt with rewarded ads:

@interface adRewarded : NSObject
/// The interstitial ad.
@property(nonatomic, strong) GADRewardedAd *rewarded;
@property (strong, nonatomic) GADRequest *request;
@end

@implementation adRewarded

-(id)init {
    [self createAndLoadRewarded];
    NSLog(@"adRewarded init");
    return self;
}

- (void)createAndLoadRewarded {
    self.rewarded = [[GADRewardedAd alloc] initWithAdUnitID:@"ca-app-pub-3940256099942544/4411468910"]; // test id
    UIWindow *window = [UIApplication sharedApplication].keyWindow;
    UIViewController *rootViewController = window.rootViewController;
    self.rewarded.delegate = self;

    GADRequest *request = [GADRequest request];
    request.testDevices = @[ kGADSimulatorID, @"2077ef9a63d2b398840261c8221a0c9a" ];
    [self.rewarded loadRequest:request];
    NSLog(@"createAndLoadRewarded");
}

- (void)interstitialWillDismissScreen:(GADRewardedAd *)ad {
    //  Method for reloading the object so that you can show ads again
    NSLog(@"rewardedWillDismissScreen");
    [self createAndLoadRewarded];
}

- (void)RewardedView {  // show interstitial ADS
    if (self.rewarded.isReady) {
        NSLog(@"Show rewarded ADS!");
        UIWindow *window = [UIApplication sharedApplication].keyWindow;
        UIViewController *rootViewController = window.rootViewController;
        [self.rewarded presentFromRootViewController:rootViewController];
    } else {
        NSLog(@"rewarded Ad wasn't ready");
    }
}
@end

And I obtain an error on the line : self.rewarded.delegate = self;
The error is : Property 'delegate' not found on object of type 'GADRewardedAd'

Just for info to start the ad in Python I am using the following code:

from pyobjus import autoclass
current_ad = autoclass("adInterstitial").alloc().init()
current_ad.show()

I also tried to use the Google documentation https://developers.google.com/admob/ios/rewarded#objective-c to create a new version but I struggle with the object named ViewController.

Either I get this error if I just copy paste the example:
Cannot find interface declaration for ViewController; did you mean UIViewController

or I get this error if I replace with UIViewController:

Cannot synthesize weak property in file using manual reference counting

Would you please know how to solve it ?

Thank you in advance!