How to properly display UIActivityIndicatorView on UICollectionView?

Question

Objective-C

Hello.
UICollectionView dynamically loads elements from the network. One line has 2 elements. When the user scrolls to the bottom, a new piece of data is loaded.

- (void)scrollViewDidScroll:(UIScrollView *)scrollView {
    NSInteger currentOffset = scrollView.contentOffset.y;
    NSInteger maximumOffset = scrollView.contentSize.height - scrollView.frame.size.height;
    
    if ((maximumOffset - currentOffset <= 70.0) && (self.requestSended == NO)) {
        NSRange range = NSMakeRange(self.products.allKeys.count, 10);
        [self loadProductsWithRange:range];
    }
}

Tell me how to correctly display UIActivityIndicatorView at the moment when a new piece of data is being loaded?