Searching for a return is supported in different ways:

The search bar on the top of the screen

You can enter any RMA number in the search bar. As a result, the return will appear in the return overview.

The return overview

You can enter any RMA number in the return reference field of the return overview header. As a result, the return will appear in the return overview.

Customer search in the right-side widget panel

The widget panel can be opened with the widget button in the top of the screen. In the widget panel, a customer widget will appear that allows you to search for a customer. As a result, the customer details will appear including a list of the most recent returns. You can click a return and as a result, the return details will appear.