This snippet will send files uploaded to a Gravity Forms form to your Amazon S3 account. To get started, first download the files. Then, some customization steps are required before use:
The code snippet is in the link below:
This type of functionality is best to put into a plugin. Theme files (i.e. functions.php) are intended for presentation and everything else should be in a plugin. This is because you’ll lose the functionality if you switch themes. Here’s a link on how to build a plugin for it.
Once you create the plugin and the main file, just add a folder called “inc” and add the S3.php file to that.