I'm building a Lumen app. I'm trying to use interface for my repositories. All my logic is wrapped in a composer package.

Here's my vendor/package/src/app/Providers/PackageServiceProvider.php:

<?php

namespace Vendor\Package\App\Providers;

use Illuminate\Support\ServiceProvider;

class SmsBackendCoreServiceProvider extends ServiceProvider
{
    protected $defer = false;

    public function register()
    {
        $this->app->bind(
            'Vendor\Package\App\Repositories\Contracts\SmsService',
            'Vendor\Package\App\Repositories\Services\SmsJson'
        );
    }

    public function boot()
    {
        $this->app->group(
            ['namespace' => 'Vendor\Package\App\Http\Controllers'],
            function ($app) {
                require __DIR__.'/../../routes/web.php';
            }
        );
    }
}

Here is my vendor/package/src/routes/web.php:

<?php

$app->get('/sms/send.json', 'JsonController@send');

Here is my vendor/package/src/app/Http/Controllers/JsonController.php:

<?php

namespace Vendor\Package\App\Http\Controllers;

use Vendor\Package\App\Http\Controllers\BaseController;
use Vendor\Package\App\Repositories\Contracts\SmsService;

class JsonController extends BaseController
{
    public $service;

    public function __construct(SmsService $service)
    {
        $this->service = $service;
    }

    public function send()
    {
        $response = $this->service->sendSms(1, 2, 3);

        return $response;
    }
}

Here is my vendor/package/src/app/Repositories/Contracts/SmsService.php:

<?php

namespace Vendor\Package\App\Repositories\Contracts;

class SmsService
{
    public function sendSMS($from, $to, $text);
}

Finally, here is my vendor/package/src/app/Repositories/Services/SmsJson.php:

<?php

namespace Vendor\Package\App\Repositories\Services;

use Vendor\Package\App\Repositories\Contracts\SmsService;

class SmsJson implements SmsService
{
    public function sendSMS($from, $to, $text)
    {
        echo 'success';
    }
}

When I try to access http://mydomain.dev/sms/send.json, I get this error:

FatalErrorException in SmsService.php line 7: Non-abstract method Mitto\SmsBackendCore\App\Repositories\Contracts\SmsService::sendSMS() must contain body

Where did I go wrong?