Official documentation for Forms & Html for The Laravel/Lumen Framework can be found at the LaravelCollective website.

composer require vluzrmos/collective-html

On your bootstrap/app.php:

$app->register('Collective\Html\HtmlServiceProvider');

class_alias('Collective\Html\HtmlFacade', 'Html');

class_alias('Collective\Html\FormFacade', 'Form');

And remember to enable de facades, just uncomment that line:

$app->withFacades()

If you want to automatically inject the $html and $form variables on all your Blade's View:

$app->register('Collective\Html\InjectVarsServiceProvider');

And now you will not need the facades anymore, just that:

{!! $form->open() !!}
//...
{!! $html->asset() !!}

That package is just a free modification of LaravelCollective/Html to work with Lumen Framework.