# Amazon S3 pre-signed POSTs with AWS SDK for PHP Version 3
Much like pre-signed URLs, pre-signed POSTs enable you to give write access to a user without giving them AWS credentials. Pre-signed POST forms can be created with the help of an instance of [AwsS3PostObjectV4](https://docs.aws.amazon.com/aws-sdk-php/v3/api/class-Aws.S3.PostObjectV4.html).
The following examples show how to:
+ Get data for an S3 Object POST upload form using [PostObjectV4](https://docs.aws.amazon.com/aws-sdk-php/v3/api/class-Aws.S3.PostObjectV4.html).
All the example code for the AWS SDK for PHP is available [here on GitHub](https://github.com/awsdocs/aws-doc-sdk-examples/tree/main/php/example_code).
## Credentials
**Note**
`PostObjectV4` does not work with credentials sourced from AWS IAM Identity Center.
Before running the example code, configure your AWS credentials, as described in [Authenticating with AWS using AWS SDK for PHP Version 3](credentials.md). Then import the AWS SDK for PHP, as described in [Installing the AWS SDK for PHP Version 3](getting-started_installation.md).
## Create PostObjectV4
To create an instance of `PostObjectV4`, you must provide the following:
+ instance of `Aws\S3\S3Client`
+ bucket
+ associative array of form input fields
+ array of policy conditions (see [Policy Construction](https://docs.aws.amazon.com/AmazonS3/latest/dev/HTTPPOSTForms.html) in the Amazon Simple Storage Service User Guide)
+ expiration time string for the policy (optional, one hour by default).
**Imports**
```
require '../vendor/autoload.php';
use Aws\S3\PostObjectV4;
use Aws\S3\S3Client;
```
**Sample Code**
```
require '../vendor/autoload.php';
use Aws\S3\PostObjectV4;
use Aws\S3\S3Client;
$client = new S3Client([
'profile' => 'default',
'region' => 'us-east-1',
]);
$bucket = 'amzn-s3-demo-bucket10';
$starts_with = 'user/eric/';
$client->listBuckets();
// Set defaults for form input fields.
$formInputs = ['acl' => 'public-read'];
// Construct an array of conditions for policy.
$options = [
['acl' => 'public-read'],
['bucket' => $bucket],
['starts-with', '$key', $starts_with],
];
// Set an expiration time (optional).
$expires = '+2 hours';
$postObject = new PostObjectV4(
$client,
$bucket,
$formInputs,
$options,
$expires
);
// Get attributes for the HTML form, for example, action, method, enctype.
$formAttributes = $postObject->getFormAttributes();
// Get attributes for the HTML form values.
$formInputs = $postObject->getFormInputs();
?>
PHP
```