STM32L552xx USB low speed mode?

[xinu2021]

Can STM32 USB device (ACM) be configured as a LOW SPEED device? It seems like USB SW and HW doesn't support configuring a low speed ACM device. Any help is appreciated in advance. From page 1953 of Ref. Manual:

[waclawek.jan]

No, the USB device in 'L5xx is Full-Speed only.

I don't know what do you mean by ACM and also don't understand why would you want to use STM32 as low-speed USB device.

JW