Each account comes with access keys that allow files to be shared to your account.
To locate your access keys, click your username on the top right and go to Access Keys. Here you will find all your active Access Keys.
To create a new Access Key, click Generate an Access Key. Enter a name for this Acess Key. Check the box for the claims you want to be associated with your access key (create, read, update, delete, details, and/or analytics). Click Generate Key to create the Access Key. You will be given your Access Key Token on the next screen. You should make a copy of this token because this will never be shown again in your account. An email will be sent letting you know an access key was created.
If you want to disable an Access Key, click the red Revoke button next to that key. This will remove this Access Key and disable any devices that are currently using it.