How do I play extra time in a knockout game?

When a knockout game is tied at full time and its tiebreak rule is Extra Time, the match management panel shows a “Start Extra Time” button (with an “Edit rules” option next to it). Extra time is played as 1 or 2 short halves of the configured length (default 5 minutes each). Goals scored in extra time count normally and appear on the scoreboard and stream overlay, labelled E-T1 / E-T2. If the score is still level after extra time, the “if still a draw” rule applies, by default a penalty shootout.