If still anyone is looking for it you can try this.
In Laravel 8 get method doesn't support logout route you can try post method like below.
<form method="POST" action="{{ route('logout') }}">
@csrf
<div class="nav-item">
<a class="nav-link" href="{{ route('logout') }}" onclick="event.preventDefault();
this.closest('form').submit(); " role="button">
<i class="fas fa-sign-out-alt"></i>
{{ __('Log Out') }}
</a>
</div>
</form>
You can also try this by check in if it's login then it will show you logout otherwise it will show you login .
@if (auth()->id())
<form method="POST" action="{{ route('logout') }}">
@csrf
<div class="nav-item">
<a class="nav-link" href="{{ route('logout') }}" onclick="event.preventDefault();
this.closest('form').submit(); " role="button">
<i class="fas fa-sign-out-alt"></i>
{{ __('Log Out') }}
</a>
</div>
</form>
@else
<li class="nav-item">
<a class="nav-link" href="{{ route('login') }}" role="button">
<i class="fas fa-sign-in-alt"></i>
Login
</a>
</li>
@endif