You can absolutely implement autofocus which conforms to WCAG. In OP's example, you can imagine the authenticator code input being shown in a modal, and from yo

You can absolutely implement autofocus which conforms to WCAG. In OP's example, you can imagine the authenticator code input being shown in a modal, and from your link, example 3 of correctly implementing focus order: > A Web page implements modal dialogs via scripting. When the trigger button is activated, a dialog opens and focus is set to the first interactive element in the dialog.