<?php

$file = 'data.csv';
$data = [];

if (file_exists($file)) {

    $handle = fopen($file, 'r');

    while (($row = fgetcsv($handle)) !== false) {
        $data[] = [
            "number" => $row[0]
        ];
    }

    fclose($handle);
}

header('Content-Type: application/json');
echo json_encode($data);
?>