1. Create a SOAP role: click on menu System --> Web Services --> SOAP/XML-RPC – Roles and click on “Add New Role” button. Enter a role name (e.g. AdminRole) and the Magento administrator password.
2. Click on “Role Resources” and select the Sales subtree. Finally, click on “Save Role” button.
3. Create a SOAP user: click on menu System --> Web Services --> SOAP/XML-RPC – Users and click on “Add New User” button. Enter a username, first name, last name, e-mail address, Magento administrator password and a password for the user in the API Key field. Keep the API key in a safe place because it will not be visible after saving the user.
5. Click on “User Role” and select the role you created earlier. Finally, click on “Save User” button.