Short connection 'hiccups' are usually buffered over and are not noticed by the user. If you have completely lost your connection while recording an application or interview, have accidentally closed the browser tab or your browser, or your computer has crashed or been disconnected, you should still be able to re-join the interview using the invitation link in your email (as long as the deadline has not yet passed). You will then be taken back to where you left off and can continue your interview.
If your interview was interrupted and you cannot complete it by re-joining or the deadline has passed, please get in touch with the contact person of the company you applied to.