[2] Through her family, she started her biathlon at an early age and won several competitions in the Italian junior division.

[3] At the 2019/20 season, she competed in four races at the World Youth Championships and made her debut in the IBU Junior Cup, where she finished on the podium once in the sprint and twice in the single mixed relay with Michele Molinari.

[4][5] In January 2021, at the age of 19, Passler made her debut in the IBU Cup, the second-highest competition series in international biathlon.

[7] On 11 December she received her career first IBU World cup medal in the women's relay race in Hochfilzen, Austria.

One month later, she also won a bronze medal along with Comola, Wierer, and Vittozzi in the relay competition in Ruhpolding, Germany.