1. How does facebook detects this type of browsers ?
2. Is there any way to tricked that and make it as a native web browser such as a js code or something elese ?

for your account security, logging in to Facebook from an embedded browser is disabled. To continue, download and log in to the Facebook app on your device and try agian.

I am using flutter webview:

WebView(
   javascriptMode: JavascriptMode.unrestricted,
   initialUrl: 'https://www.facebook.com/',
   onPageFinished: controller.webViewOnPageFinished,
)