Xcode – Objective-C warning: Class 'ViewController' does not conform to protocol 'CBPeripheralManagerDelegate'

I’m trying to create an Obj-C, CoreBluetooth virtual peripheral app and get this warning.

//
//  ViewController.h
//  sim_backend_empty3
//
//

#import <UIKit/UIKit.h>
#import <CoreBluetooth/CoreBluetooth.h>

@interface ViewController : UIViewController  <CBPeripheralManagerDelegate>

@property (nonatomic, strong) CBPeripheralManager *peripheralManager;

@end


//
//  ViewController.m
//  sim_backend_empty3
//
//

#import "ViewController.h"

@implementation ViewController   >>>>>>>>>> WARNING >>>>>>>>>>   Class 'ViewController' does not conform to protocol 'CBPeripheralManagerDelegate'

- (void)viewDidLoad {
    [super viewDidLoad];
}

-(void)start_BLE_advertisements
{
    [[CBPeripheralManager alloc] initWithDelegate:self queue:nil options:nil];
    
}


@end