https://github.com/LasseRafn/php-dinero Invoice example

create-invoice.php

<?php

// Create Instance
$dinero = new \LasseRafn\Dinero\Dinero( $clientId, $clientSecret ); // Client ID + Secret gotten from Dinero

// Auth to a Dinero account
$dinero->auth( $apiKey, $orgId ); // API key created in Dinero + company ID (bottom left when logged in)
 
// Create the invoice
$invoice = $dinero->invoices()->create([
  'ContactGuid' => '123', // Customer/contact Guid  
  'Description' => 'Service Faktura',
  'ProductLines' => [
    [ // Line Documentation: https://api.dinero.dk/v1/docs/ResourceModel?modelName=InvoiceLineCreate
      "BaseAmountValue": 20.0,
      // "ProductGuid": "54691c12-2172-404e-b6f0-3e3ae380fdbe", // Set this if you're using products in Dinero
      "Description": "Flowers", // Leave this empty, IF you have set the ProductGuid
      "Comments": "Smells good",
      "Quantity": 5.0,
      "AccountNumber": 1000,
      "Unit": "parts",
      "Discount": 10.0,
      "LineType": "Product"
    ]
  ] 
]);