Fatal error: Uncaught Error: Class 'MongoDB\Driver\Manager'

Hello, I am testing the MongoDB connection via PHP native driver in Local as a testing environment. Note that I have followed installation procedures from MongoDB’s PHP Driver documentation regarding pecl install of the extension and composer install of mongodb into the root directory.

When I try to run a test connection via the driver, I receive the following fatal error notifications.

( ! ) Fatal error: Uncaught Error: Class ‘MongoDB\Driver\Manager’ not found in /Users/michaeldemiceli/Local Sites/cora-dev/app/public/wp-content/plugins/MongoDB/conf/vendor/mongodb/mongodb/src/Client.php on line 124

( ! ) Error: Class ‘MongoDB\Driver\Manager’ not found in /Users/michaeldemiceli/Local Sites/cora-dev/app/public/wp-content/plugins/MongoDB/conf/vendor/mongodb/mongodb/src/Client.php on line 124

This is the code I am using just to load the test connection onto a blank admin page:

function cora_mongodb_admin_menu()
{
    add_menu_page(
        'MongoDB',
        'MongoDB',
        'manage_options',
        'cora_mongodb_admin',
        'cora_mongodb_admin_page'
    );
}
add_action('admin_menu', 'cora_mongodb_admin_menu');

function cora_mongodb_admin_page()
{
    require_once dirname(__FILE__) . "/conf/conf.php";
}

Which pulls the following code from conf.php:

<?php

require_once dirname( __FILE__ ) . '/vendor/autoload.php';

$client = new MongoDB\Client(
    'mongodb+srv://<my-database>:<my-password>@<my-cluster>.lkffbtl.mongodb.net/?retryWrites=true&w=majority');

$db = $client->test;

**Note: I did input the actual variables into my code for database, password, and cluster.

Following the error reference to the src/Client.php file, I see the following code block around the point of error:

    public function __construct($uri = 'mongodb://127.0.0.1/', array $uriOptions = [], array $driverOptions = [])
    {
        $driverOptions += ['typeMap' => self::$defaultTypeMap];

        if (! is_array($driverOptions['typeMap'])) {
            throw InvalidArgumentException::invalidType('"typeMap" driver option', $driverOptions['typeMap'], 'array');
        }

        if (isset($driverOptions['autoEncryption']['keyVaultClient'])) {
            if ($driverOptions['autoEncryption']['keyVaultClient'] instanceof self) {
                $driverOptions['autoEncryption']['keyVaultClient'] = $driverOptions['autoEncryption']['keyVaultClient']->manager;
            } elseif (! $driverOptions['autoEncryption']['keyVaultClient'] instanceof Manager) {
                throw InvalidArgumentException::invalidType('"keyVaultClient" autoEncryption option', $driverOptions['autoEncryption']['keyVaultClient'], [self::class, Manager::class]);
            }
        }

        $driverOptions['driver'] = $this->mergeDriverInfo($driverOptions['driver'] ?? []);

        $this->uri = (string) $uri;
        $this->typeMap = $driverOptions['typeMap'] ?? null;

        unset($driverOptions['typeMap']);

        $this->manager = new Manager($uri, $uriOptions, $driverOptions);
        $this->readConcern = $this->manager->getReadConcern();
        $this->readPreference = $this->manager->getReadPreference();
        $this->writeConcern = $this->manager->getWriteConcern();
    }

For reference, line 124 from the code block above (which is throwing the error) is:
$this->manager = new Manager($uri, $uriOptions, $driverOptions);

This code comes directly from the composer installation of mongodb, and has not been edited at all.

I appreciate any insight form the team or anyone who has had this same problem in trying to debug so that the code will properly establish the connection to the database.

Thank you!