B-L4S5I-IOT01A currently does not support?

[GZent.1]

Target device 'B-L4S5I-IOT01A' currently does not support STM32CubeIDE

also in Mbed, any advice on how to start using it?

[GZent.1]

Can I use B-l475E?

[LaurentL]

STM32CubeIde v1.4.0 supports this B-L4S5I-IOT01A board.

Download and install the new version and enjoy.