how to secure login form in React Router?

I have a small piece of code using React and React router, like:

<Route path='/' render={({location}) => (
        loggedIn ? (
          <ProtectedContent/>
        ) : (
          <Login/>
        )
      )}/>

my question is when its minified and deployed, may be any attacker can play with the modified code and change that loggedIn with true and bypass the form, is there a way to secure it?