Please follow the steps below:

• Sign in to your account.
• Go to the Checkout Settings.
• Set Redirect and Callback URLs
• Copy private token, you will use this private token to connect Paracoin API.
• After that there will be 2 steps:

1. Create a form and send POST request as below:

<?php
    // This is an HTML & PHP example

    $paraData = base64_encode(json_encode([
        "receiver" => "YOUR_PARA_ADDRESS",
        "orderToken" => "UNIQUE_ORDER_TOKEN",
        "info" => "PRODUCT_INFO",
        "amount" => 10,
        "customAmount" => 0,
    ]));

    echo "<a href='https://paracoin.network/checkout/$paraData'>Submit Payment</a>";
?> 

• receiver - Your Paracoin address.
• orderToken - The unique identifier for the order
• info - Transaction info
• amount - Payment amount
• customAmount - Set 1 to allow customers to edit and enter a custom amount. Default is 0 and prevents amount editing.

2. Receive callback and process the order:

<?php
    // This is a PHP callback example

    $receiver = "YOUR_PARA_ADDRESS";
    $privateToken = "YOUR_PRIVATE_TOKEN";

    $orderToken = $_POST["orderToken"];
    $receiver = $_POST["receiver"];
    $amount = $_POST["amount"];
    $orderHash = $_POST["orderHash"];
    $debugMode = $_POST["debugMode"];

    $hash = md5($orderToken.$receiver.$amount.$privateToken);

    if ( $hash != $orderHash || $debugMode) return 0;

    // You can add more filters and security checks depending on your needs.
    
    // Process the order here.

    return 1;

?> 

• receiver - Your Paracoin address.
• privateToken - You can find your private token on the checkout settings.
• orderToken - The unique identifier for the order
• amount - Payment amount
• orderHash - MD5 hash of order token, receiver, amount and private token.
• debugMode - If you turn on debug Mode on the checkout settings, debugMode will be true, otherwise false.