How to access Smartsheet from PHP API?

It is my first time trying to connect Sheet from Smartsheet using API with PHP.
I cannot seem to connect and give me this error

Notice: Trying to get property of non-object in C:\xampp\htdocs\smartsheet\test.php on line 22

The variable $sheetObj is empty.
And in Authorization: Bearer, what does Bearer means? Is it a token name or it is always Bearer?

My future plan is to write into the row of smartsheet using PHP. Can anyone give me advice what went wrong with my code?

$baseURL = "https://api.smartsheet.com/1.1";
$sheetsURL = $baseURL . "/sheets/";
$getSheetURL = $baseURL . "/sheet/xxxxxxxxxxx";
$rowsURL = $baseURL . "/sheet/xxxxxxxxxxx/rows";

$accessToken = "xxxxxxxxxxxxxxxxxx"; 

// Create Headers array for cURL
$headers = array(
    "Authorization: Bearer " . $accessToken,
    "Content-Type: application/json"
);  

$curlSession = curl_init($getSheetURL);
curl_setopt($curlSession, CURLOPT_HTTPHEADER, $headers);
curl_setopt($curlSession, CURLOPT_RETURNTRANSFER, TRUE);
$getSheetResponseData = curl_exec($curlSession);

$sheetObj = json_decode($getSheetResponseData);
echo "<h1>Sheet name: ". $sheetObj->name ."</h1>";

Solution

Both stmcallister and Kim provided good information on how to troubleshoot your issue and some likely causes.

There were actually two issues with the code you provided.

As Scott mentioned you must point to the 2.0 version of the API.
```
$baseURL = "https://api.smartsheet.com/2.0";
```
You have a typo in your $getSheetURL. As is documented here the url is /sheets/{sheetId}. So your code should have the following:
```
$getSheetURL = $baseURL. "/sheets/xxxxxxxxxxx";
```

Here is your code in a working state. Make sure to replace YOUR_TOKEN and also take a look at the output from var_dump (which I added to your code) to see what message it gives you.

<?php
$baseURL = "https://api.smartsheet.com/2.0";
$getSheetURL = $baseURL. "/sheets/4925037959505796";
$accessToken = "YOUR_TOKEN"; 

$headers = array("Authorization: Bearer ". $accessToken);

$curlSession = curl_init($getSheetURL);
curl_setopt($curlSession, CURLOPT_HTTPHEADER, $headers);
curl_setopt($curlSession, CURLOPT_RETURNTRANSFER, TRUE);
$getSheetResponseData = curl_exec($curlSession);

// Remove this line when done debugging
var_dump($getSheetResponseData);

$sheetObj = json_decode($getSheetResponseData);

echo "<h1>Sheet name: ". $sheetObj->name ."</h1>";
?>