iPhone X Font Size Settings

i'm using a webview and depending on the text size slider on the real device i got a different layout...

in earlier versions of xcode/ios simulator i could change the setting in the settings app on the simulator... that setting is now gone...

EDIT:

i now understand, that the problem seems to be something different... even if that user changes the text size setting, the page is not displayed as in the simulator... it seems to be that the webview does not pay attention the css settings like

margin-top: constant(safe-area-inset-top);

>seems to be that the webview does not pay attention

WebView is deprecated on iOS as of iOS 8 - WKWebView is the current implementation otherwise.