How can I move a message to a folder from the message window using the keyboard?

By "message window", I mean the window that opens to read the message.

I know how to do it from the main window, but my workflow is to process messages while I have them open, which includes filing as necessary. Also, I minimize my use of the mouse.

I am using KMail Version 5.13.3 (19.12.3) on Lubuntu 20.04.2 LTS.