Hello @Othmane1,
You did not specify the part number.
But yes, this is possible.
The CS selected in the LPSPI module does not have to be routed to a pin.
A GPIO can be used instead, but it would be your responsibility to assert and deassert the GPIO.
Why do you need that?
The LPSPI module allows configuring the PCS delays, frame size etc, it also allows continuous transfers with the CS asserted over multiple frames.
Regards,
Daniel