Chromium is opensource the snapshot code is at: https://github.com/chromium/chromium/blob/872b635eb1e5ddecbebca7f065589b60a4065d7e/ios/web/web_state/ui/crw_web_controller.mm#L734C1-L735C62

uses WKUIDelegate's - (nullable WKWebView *)webView:(WKWebView *)webView createWebViewWithConfiguration:(WKWebViewConfiguration *)configuration forNavigationAction:(WKNavigationAction *)navigationAction windowFeatures:(WKWindowFeatures *)windowFeatures;

@interface UICornerStyle : NSObject <NSCopying> + (instancetype)fixedWithRadius:(double)arg2; @end @interface UICornerConfiguration : NSObject <NSCopying> + (instancetype)uniform:(UICornerStyle*)arg2; @end @interface UIVisualEffectView (Helper) - (void)setCornerConfiguration:(UICornerConfiguration *)arg1; @end add this header file to your project