Consuming an API using CURL in php

Question

I am trying to consume an API, and anytime I send the data to the API, I get a "No data sent" response from the API. below is my code.

<?php
$url = 'endpoint'; 
$curl = curl_init();
$valu = array(
    'username' => 'used',
    'firstname' => 'user',
    'email' => 'user@email.com',
    'bio' => 'A very good personality',
    'lastname' => 'demo',
    'password' => 'date'
);
$json_string = json_encode(array( "data" => $valu));
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_POST, TRUE);
curl_setopt($curl, CURLOPT_POSTFIELDS, $json_string);
curl_setopt($curl, CURLOPT_HTTPHEADER, array('Content-Type:application/json'));
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true );
$data = curl_exec($curl);
if($data){
    echo $data;
}
curl_close($curl);
?>

below is data the API requires from the client

{
"username":"username",
"firstname":"firstname",
"email":"email",
"bio":"A very good personality",
"lastname":"lastname",
"password":"data"
}

inside a node called 'data'

Please, help

Answer 1

I am providing with example, it worked for me!

<?php
$url = 'https://reqres.in/api/users'; 
$curl = curl_init($url);-> this line is incorrect
$valu = array(
    'name' => 'used',
    'job' => 'user'
);
$json_string = json_encode(array( "data" => $valu));
curl_setopt($curl, CURLOPT_URL, $url);
curl_setopt($curl, CURLOPT_POST, TRUE);
curl_setopt($curl, CURLOPT_POSTFIELDS, $json_string);
curl_setopt($curl, CURLOPT_HTTPHEADER, array('Content-Type:application/json'));
curl_setopt($curl, CURLOPT_RETURNTRANSFER, true );
$data = curl_exec($curl);
if($data){
    echo $data;
}
curl_close($curl);
?>