It's just that if Lazio plays defensively well enough then they have a chance to end the match with a draw and they will qualify for the next round. But Harry Kane will definitely work hard to score goals and bring Bayern Munich through to the next round.
Playing defensively against a team like Bayern can easily hurt you or work out well for you. It's a risk that has to be managed properly. If you want to defend against Bayern, you have to make sure you don't leave any room for error. A single mistake can make them hurt you. You also need to be very good on the counterattack. Fast wingers and quick passes.
I believe they'll stand a better chance if they also attack Bayern. Don't let them be comfortable on the ball and press them. When Bayern are comfortable on the ball they can easily hurt you.
It's going to be a very difficult game for Lazio but if they put their heads down and work enough they can win or draw the match.