How to create autoincrement sequence number in MongoDB, with PHP library

mongodb-autoincrement.php

<?php

// Table "counters", stores autoincrement value (seq)
/* 
   
   Initial value are:

   {
      "_id": "nota",  // Counter key, eg: 'nota'
      "seq": 1        // Initial number
   }
   
*/   

//..............

// Link to table "counters"
$counters = $client->mydatabase->counters;

// Link to any tables 
$table = $client->mydatabase->mytable;

// Insert one record to the table
$result = $table->insertOne([
    'nomor_nota' => getNextSequence( $counters, "nota" ), // Get next autoincrement of 'nota'
    'customer' => 'Udin Balagadona',
    'total' => 5000000
]);

//..............

// Function to get next autoincrement number
function getNextSequence( $counters, $name ) {
    $result =  $counters->findOneAndUpdate(
                [ '_id' => 'nota' ], // Set key as 'nota'
                [ '$inc' => [ 'seq' => 1] ],
                [ 'upsert' => true,
                  'projection' => [ 'seq' => 1 ],
                  'returnDocument' => MongoDB\Operation\FindOneAndUpdate::RETURN_DOCUMENT_AFTER
                ]
    );
    return $result['seq'];
}