Microsoft graph Unable to read JSON request payload - php

Question

I'm trying to create subscriptions with microsoft graph in php, however I am unable to see what is going wrong at this point.
The code is breaking at the following:
protected $http_subscribe = "https://graph.microsoft.com/v1.0/subscriptions";
public function getSubscriptions()
{
if(empty($this->token)) {
dd('no token supplied'); //some debugging
}
$date = $this->endTimeDate->format('Y-m-d'); //This is Carbon date
$time = $this->endTimeDate->format('H:i:s.u');
$response = $this->client->request('POST', $this->http_subscribe, [
'headers' => [
'Authorization' => 'Bearer ' . $this->token,
'Content-Type' => "application/json"
], 'form_params' => [
"changeType" => "created,updated",
"notificationUrl" => "https://website.test/notify",
"resource" => "me/mailFolders('Inbox')/messages",
"expirationDateTime" => $date.'T'.$time,
"clientState" => "secretClientValue"
]
]);
dd($response);
}
The full error I'm getting is:
"""
{\r\n
"error": {\r\n
"code": "BadRequest",\r\n
"message": "Unable to read JSON request payload. Please ensure Content-Type header is set and payload is of valid JSON format.",\r\n
"innerError": {\r\n
"request-id": "063d9947-80fd-461d-a70e-q0bd8eee9d56",\r\n
"date": "2018-08-07T08:20:54"\r\n
}\r\n
}\r\n
}
"""
Now I get what the error says, my json would be invalid, however this array is in correct json format, I'm using Guzzle as my Client.

Answer 1

You should use json option. Try this:
$response = $this->client->request('POST', $this->http_subscribe, [
'headers' => [
'Authorization' => 'Bearer ' . $this->token,
],
'json' => [
"changeType" => "created,updated",
"notificationUrl" => "https://website.test/notify",
"resource" => "me/mailFolders('Inbox')/messages",
"expirationDateTime" => $date.'T'.$time,
"clientState" => "secretClientValue",
],
]);