Sign in with a username on the Filament login page

AdminPanelProvider.php

<?php

namespace App\Providers\Filament;

use App\Filament\Pages\Auth\Login;
use Filament\Http\Middleware\Authenticate;
use Filament\Http\Middleware\DisableBladeIconComponents;
use Filament\Http\Middleware\DispatchServingFilamentEvent;
use Filament\Pages;
use Filament\Panel;
use Filament\PanelProvider;
use Filament\Support\Colors\Color;
use Filament\Widgets;
use Illuminate\Cookie\Middleware\AddQueuedCookiesToResponse;
use Illuminate\Cookie\Middleware\EncryptCookies;
use Illuminate\Foundation\Http\Middleware\VerifyCsrfToken;
use Illuminate\Routing\Middleware\SubstituteBindings;
use Illuminate\Session\Middleware\AuthenticateSession;
use Illuminate\Session\Middleware\StartSession;
use Illuminate\View\Middleware\ShareErrorsFromSession;

class AdminPanelProvider extends PanelProvider
{
    public function panel(Panel $panel): Panel
    {
        return $panel
            ->default()
            ->id('admin')
            ->path('admin')
            ->login(Login::class)
            ->colors([
                'primary' => Color::Amber,
            ])
            ->discoverResources(in: app_path('Filament/Resources'), for: 'App\\Filament\\Resources')
            ->discoverPages(in: app_path('Filament/Pages'), for: 'App\\Filament\\Pages')
            ->pages([
                Pages\Dashboard::class,
            ])
            ->discoverWidgets(in: app_path('Filament/Widgets'), for: 'App\\Filament\\Widgets')
            ->widgets([
                Widgets\AccountWidget::class,
                Widgets\FilamentInfoWidget::class,
            ])
            ->middleware([
                EncryptCookies::class,
                AddQueuedCookiesToResponse::class,
                StartSession::class,
                AuthenticateSession::class,
                ShareErrorsFromSession::class,
                VerifyCsrfToken::class,
                SubstituteBindings::class,
                DisableBladeIconComponents::class,
                DispatchServingFilamentEvent::class,
            ])
            ->authMiddleware([
                Authenticate::class,
            ]);
    }
}

Login.php

<?php

namespace App\Filament\Pages\Auth;

use Filament\Forms\Components\Component;
use Filament\Forms\Components\TextInput;
use Filament\Forms\Form;
use Filament\Pages\Auth\Login as BaseAuth;

class Login extends BaseAuth
{
    public function form(Form $form): Form
    {
        return $form
            ->schema([
                $this->getUsernameFormComponent(),
                $this->getPasswordFormComponent(),
                $this->getRememberFormComponent(),
            ])
            ->statePath('data');
    }

    protected function getUsernameFormComponent(): Component
    {
        return TextInput::make('username')
            ->required();
    }

    protected function getCredentialsFromFormData(array $data): array
    {
        return [
            'username' => $data['username'],
            'password' => $data['password'],
        ];
    }
}