_curl.php

$url="https://checkout.simplepay.ng/v2/payments/form/";
    $fields=array('key'=>'test_pu_18fb91d02d7c4be5a386309c882bd176',
        'description'=>'holla i am here',
        'payment_type'=>'checkout' ,
        'amount' => $subtotal,
        'email' => $email,
        'currency'=>'NGN',
        'payment_id'=>'XVTID',
        'success_url'=>'http://localhost/tender/tender/epayments/confirmation',
        'cancel_url'=>'http://localhost/tender/tender/epayments/confirmation',
        'fail_url' => 'http://localhost/tender/tender/epayments/confirmation'
        );
    $ch = curl_init();
    curl_setopt($ch, CURLOPT_HTTPHEADER, array('Content-Type: application/json'));
    curl_setopt($ch, CURLOPT_URL, $url);
    curl_setopt($ch, CURLOPT_POST,1);
    curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($fields));

    $result = curl_exec($ch);
    if (curl_errno($ch)){
        debug(curl_error($ch));
    }else{
        curl_close($ch);
     }