https://www.epo.org/en/service-support/faq/learning/european-patent-administration-certification/am-i-allowed-use-keyboard

Am I allowed to use keyboard shortcuts, special keys combinations, such as Alt+Tab, and touchpad gestures in the lockdown browser?

You are not allowed to use shortcuts (Alt+Tab, Ctrl+P or the like), key combinations and touchpad gestures in the lockdown browser, except the ones mentioned below. Using shortcuts is seen as an unauthorised action and can result in the lockdown browser to stop your examination.

The following Windows shortcuts are allowed, but only work in the editor (not in the “external internet resources”): Ctrl+C, Ctrl+V, Ctrl+Shift+V, Ctrl+F (and the corresponding Mac shortcuts).