Twitter-api – How to post Tweets with the Twitter API V2 in PHP?

I’m trying to post tweets with the Twitter API v2 but have an error. I’m using the TwitterAPIExchange.php library, this works fine when I’m trying to search for Tweets for example with GET. But no luck with POST, see code below also the Manage Tweets doc from Twitter: https://developer.twitter.com/en/docs/twitter-api/tweets/manage-tweets/api-reference/post-tweets

Maybe I’m missing some parameters after the end point.

header('Content-Type:application/json');

include ($_SERVER["DOCUMENT_ROOT"] . "/TwitterAPIExchange.php");
 
$settings = array(
    'oauth_access_token' => "xxxx",
    'oauth_access_token_secret' => "xxxx",
    'consumer_key' => "xxxx",
    'consumer_secret' => "xxxx"
    
);

$url = "https://api.twitter.com/2/tweets";
$requestMethod = 'POST';

$postfields = array('status' => 'This is the text to Tweet');

$twitter = new TwitterAPIExchange($settings);
$response = $twitter->buildOauth($url, $requestMethod)->setPostfields($postfields)->performRequest();

Errors:

{
errors: [
{
parameters: { },
message: "Requests with bodies must have content-type of application/json."
}
],
title: "Invalid Request",
detail: "One or more parameters to your request was invalid.",
type: "https://api.twitter.com/2/problems/invalid-request"
}