/home/brandsfa/www/vendor/mercadopago/dx-php/samples/checkout-buttons/full-preference/button.php
<?php

    # Crear un boton de pago a partir de una preferencia con atributos requeridos minimos

    require_once dirname(__FILE__).'/../../index.php';

    $preference = new MercadoPago\Preference();

    # Building an item

    $item1 = new MercadoPago\Item();
    $item1->id = "00001";
    $item1->title = "item"; 
    $item1->quantity = 1;
    $item1->unit_price = 100;

    $item2 = new MercadoPago\Item();
    $item2->id = "00002";
    $item2->title = "item"; 
    $item2->quantity = 1;
    $item2->unit_price = 100;

    $preference->items = array($item1, $item2);

    $preference->payment_methods = array(
    "excluded_payment_types" => array(
        array("id" => "credit_card")
    ),
    "installments" => 12
    );

    $preference->external_reference = "A Custom External Reference";

    $preference->save(); # Save the preference and send the HTTP Request to create

    # Return the HTML code for button

    echo "<a href='$preference->sandbox_init_point'> Pagar </a>";

?>