Magento 2 Rest API Order edit - rest

Question

I'm trying to figure out how to edit an order after I requested it.
I made a custom attribute whether an order is exported or not.
I first get all orders with status not exported and after I exported them, I want to change the custom attribute to exported.
What is the REST request to edit/update an order? I keep getting error messages like:
{"message":"%fieldName is a required field.","parameters":
{"fieldName":"entity"}
This is my code:
$json = array(
"entity_id" => $id,
"extension_attributes" => array(
"custom_export_attribute" => "exported",
)
);
$webapi = new ApiClient('https://dev.local.nl', self::$username, self::$password);
$response = $webapi->getClient()->request('PUT', '/rest/V1/orders/create', [
'headers' => [
'Authorization' => "Bearer " . $webapi->getToken(),
'Content-Type' => "application/json"
],
'body' => json_encode($json)
]);
return json_decode($response->getBody(), true);
I also tried:
$webapi->getClient()->request('PUT', '/rest/V1/orders/'.$id,

Answer 1

To edit / update order details, the Magento 2 /V1/orders accepts POST request method. As per Magento 2 Dev Doc, it accepts the request body in below format (You can find whole JSON request in documentation page):
{
"entity": {
"entity_id": 0,
"extension_attributes": {
}
}
}
So, you just need to update the $json variable as:
$json = [
"entity"=> [
"entity_id" => $id,
"extension_attributes" => [
"custom_export_attribute" => "exported"
]
]
]
And than invoke with POST request method instead of PUT. In my suggestion prefer to use Create API for new order creation.