OS X Mavericks. How to switch to popup window without mouse?

Question

macOS

I really don't want to do it with the mouse, because I work with the keyboard more often.
I rummaged through several tons of useful shortcuts - there is no result.
For example, I open an image with a password through Alfred, a
window appears in which I can’t switch to the input field.

Answer 1

TAB seems to be supposed to switch.