Api Oppwa payment button, Problems with a foreach - php

Question

I am integrating a Payment Button with Oppwa API,
But with the method that brings me the "CheckoutId".
What happens I have to send all the parameters.
$total = 120;
$iva = 004012000000000012;
$totalTarifa12 = 053012000000000100;
$totalBase0 = 052012000000000200;
$email = "JonathanVeraMarin98#outlook.com";
$primer_nombre = "Jonathan";
$segundo_nombre = "Fernando";
$apellido = "Vera";
$cedula = "0952152525";
$trx = 123456789;
$ip_address = '05100817913101';
$finger = 'https://test.oppwa.com/v1/checkouts';
$merchterm= '1000000505_PD100406';
$telefono ='2172161';
$direccion_cliente = 11222;
$pais_cliente = 121212;
$direccion_entrega = '1600 Pennsylvania Ave NW';
$pais_entrega = 121212;
$checkoutId = prepareCheckout($items,$total,$iva,$totalTarifa12,$totalBase0,$email,$primer_nombre,$segundo_nombre,$apellido,$cedula,$trx,$ip_address,$finger,$merchterm,$telefono,$direccion_cliente,$pais_cliente,$direccion_entrega,$pais_entrega);
These are the values ​​of the burned parameters that I sent to the function
function prepareCheckout($items,$total,$iva,$totalTarifa12,$totalBase0,$email,$primer_nombre
,$segundo_nombre,$apellido,$cedula,$trx,$ip_address,$finger,$merchterm,
$telefono,$direccion_cliente,$pais_cliente,$direccion_entrega,$pais_entrega){
$finger = urlencode($finger);
$i =0;
$url = "https://test.oppwa.com/v1/checkouts";
$iva = str_replace('.', '', $iva);
$totalTarifa12 = str_replace('.', '', $totalTarifa12);
$totalBase0 = str_replace('.', '', $totalBase0);
$valueIva = str_pad($iva,12,'0'.STR_PAD_LEFT);
$valueTotalIva = str_pad($totalTarifa12,12,'0'.STR_PAD_LEFT);
$valueIvaTotalBase0 = str_pad($totalBase0,12,'0'.STR_PAD_LEFT);
$data = "authentication.userId=8a8294184b4f2868014b4f86f767015d" .
"&authentication.password=F8T7N4PD" .
"&authentication.entityId=8a8294184b4f2868014b4f87bf160173" .
"&amount=".$total.
"&currency=USD".
"&paymentType=DB".
"&customer.givenName=".$primer_nombre.
"&customer.middleName=".$segundo_nombre.
"&customer.surname=".$apellido.
"&customer.ip=".$ip_address.
"&customer.merchantCustomerId=00000000001".
"&merchantTransactionId=transaction_".$trx.
"&customer.email=".$email.
"&customer.identificationDocType=IDCAD".
"&customer.identificationDocId=".$cedula.
"&customer.phone=".$telefono.
"&billing.street1=".$direccion_cliente.
"&billing.country=".$pais_cliente.
"&shipping.street1=".$direccion_entrega.
"&shipping.country=".$pais_entrega.
"&risk.paramters[USER_DATA2]=MiComercio".
"customParamters[".$merchterm."]=00810030070103910004012".$valueIva.
"05100817913101052012".$valueIvaTotalBase0."053012".$valueTotalIva;
foreach ($items["cart"] as $c )
{
$data.="&cart.items[".$i."].name =".$c["product_name"];
$data.="&cart.items[".$i."].description ="."Descripcion: ".$c["product_name"];
$data.="&cart.items[".$i."].price =".$c["product_price"];
$data.="&cart.items[".$i."].quantity= ".$c["q"];
}
$data.= "&testMode=EXTERNAL";
$ch = curl_init();
curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_HTTPHEADER, array(
'Authorization:Bearer OGE4Mjk0MTg1MzNjZjMxZDAxNTMzZDA2ZmQwNDA3NDh8WHQ3RjIyUUVOWA=='));
curl_setopt($ch, CURLOPT_POST, 1);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);// this should be set to true inproduction
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
$responseData = curl_exec($ch);
if(curl_errno($ch)) {
return curl_error($ch);
}
curl_close($ch);
return $responseData;
}
My function that generates a checkoutId.
The problem I have is in the foreach I know that it is going through an array but I get an error because I don't know what the condition $ items ['cart'] refers to
foreach ($items["cart"] as $c )
{
$data.="&cart.items[".$i."].name =".$c["product_name"];
$data.="&cart.items[".$i."].description ="."Descripcion: ".$c["product_name"];
$data.="&cart.items[".$i."].price =".$c["product_price"];
$data.="&cart.items[".$i."].quantity= ".$c["q"];
}
I've tried it like this
$items = array();
$items['product_name'] = 'Software';
$items['product_name'] = 'Hola';
$items['product_price'] = '50';
$items['q'] = '1';
I hurt:
Warning: Invalid argument supplied for foreach() in C:\xampp\htdocs\Datafast\index.php on line 63
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