Working with Outlook in a browser
If CloudFiler has been enabled on your Exchange server it should be available when running Outlook in any browser but it may not be immediately obvious.
Accessing the Add-in with incoming email in a browser
There are two ways that you can access CloudFiler when reading email in the Outlook browser App. You can either select the CloudFiler icon from the top of a message, or select it from the triple-dot menu.
In either case it is a good idea to pin the Add-in when it appears.
Accessing CloudFiler when composing messages in a browser
When composing messages you should find the CloudFiler icon on the menu bar, but if it's not there try the triple-dot menu.
As recommended above, it's a good idea to pin the add-in.