Pens is an abbreviation for penalties, mate 😃
In the knockout stages of a tournament, if the scoreline is tied after 90 minutes there is an extra-time period of 30 minutes to see if one team can triumph. If the scores are still level, penalties are then used to decide the winner.
Each team gets 5 penalties each - whoever scores the most penalties, wins. Each penalty has to be taken by a different player.
However, on occasion, the ties are still level after the 5 penalties are taken… this then results in a further round of 1 penalty each (sometimes referred to as ‘sudden death penalties’) - to be taken by players who have not yet taken a penalty - and it continues until there is a winner.
Sometimes this results in both goalkeepers taking penalties, occasionally against each other - which is quite a rare event, and usually fun/entertaining to watch.
If the scores are still level after everyone has taken a penalty - it just resets back to the players who originally took the set of 5 penalties - and continues until there is a winner…
This video may show / explain it better (a 15-14 win on penalties for Liverpool a couple of years back)…
If it was up to me, if teams were still tied after the 30 minute extra time period, I would turn off the clock and have them play soccer until someone scores. (Team that scores wins the game)