Hi Keith, 

Welcome to the Box Community!

At present, Box Trash is only accessible via the Box Webapp and not on Box mobile apps. This means, you can only access Trash in your Box account by logging in to Box.com using a web browser on a computer.

For more details on managing Box Trash, please take a look at this article: https://support.box.com/hc/en-us/articles/360044196093-Managing-Trash