If user does not have FB app on the phone, fbsdk takes care that automically and shows the “web”…

If user does not have FB app on the phone, fbsdk takes care that automically and shows the “web” login interface instead of the “native” one.

One way to solve your problem is to enforce “web” login screen instead of “native”. But I would suggest to do that only after logout. Because users that have FB app and will be irritated if they don’t login automatically. Or maybe when users logout, only then intoduce an extra button that will prompt them to login as another FB user. When user clicks this new button, you will always show the “web” login screen.

LoginManager.setLoginBehavior('WEB_ONLY');