Macbook Air M1 2020 recognises dual monitor as one monitor

Hello, in the library of my university I can connect my M1 Macbook Air 2020 to a dual monitor system via USB-C cable (same as the charger). The connection works great and I can use my Mac's trackpad and keyboard or the mouse and keyboard provided with the monitors, but the two monitors mirror each other. I have the monitors as my main display and my Macbook as the extended display but I don't have the option to separate the two monitors.

Classmates that have windows system laptops can use the monitors separately but with my macbook I cannot.

Please could someone explain to me how I can use the monitors as two different displays.

Thanks.