WKWebView 无法触发拨打电话

// 处理拨打电话以及Url跳转等等- (void)webView:(WKWebView *)webView decidePolicyForNavigationAction:(WKNavigationAction *)navigationAction decisionHandler:(void (^)(WKNavigationActionPolicy))decisionHandler {    NSURL *URL = navigationAction.request.URL;    NSString *scheme = [URL scheme];    if ([scheme isEqualToString:@"tel"]) {        NSString *resourceSpecifier = [URL resourceSpecifier];        NSString *callPhone = [NSString stringWithFormat:@"telprompt://%@", resourceSpecifier];        /// 防止iOS 10及其之后，拨打电话系统弹出框延迟出现        dispatch_async(dispatch_get_global_queue(0, 0), ^{            [[UIApplication sharedApplication] openURL:[NSURL URLWithString:callPhone]];        });    }    decisionHandler(WKNavigationActionPolicyAllow);}