laravel-mongodb: Class 'MongoDB\Driver\Manager' not found

Hello, I’m using Php7.1, Laravel 5.5, and Mongo 3.4.10 as Dockers.

In the .../vendor/mongodb/mongodb/src/Client.php file, the corresponding FatalThrowableError Class 'MongoDB\Driver\Manager' not found appears on line 83.

In the Model

<? php

namespace App\Models\Mongo;

use Jenssegers\Mongodb\Eloquent\Model as Moloquent;

class Keywords extends Moloquent
{
     protected $connection = 'mongodb';
     protected $collection = 'keywords';
}

I used the code,

In the Controller,

public function keyword ()
{
     Keywords::all();
}

I used the code.

The database.php file contains

'mongodb' => [
     'driver' => 'mongodb',
     'host' => '127.0.0.1',
     'port' => '27017',
     'database' => 'test',
],

I put this code in it.

I’ve been looking for the same error since yesterday, but it’s still the same. Help is urgently needed.