You can’t, it’s against their policy, if they catch you they’ll revoke your access.
developers.facebook.com/policy/
8.2 (which states “Native IOS and Android apps that implement Facebook Login must use our official SDKs for login.” This has a help icon next to it that opens a dialog on their site that shows a couple pictures and then explains “Android apps should use the default login behavior defined by the SDK, which may use the web-view Login dialog. On iOS, only kiosk apps may use a web-view Login dialog.”