Micropython SDCard for T-RGB Board

[He-Peter-Huang]

I'm using the LilyGo T-RGB, I'm having trouble setting up the SDCard, the CS pin is connected to P07 on the XL9535. What should I put in for the SDCard cs parameter?

>>> import machine
>>> import os
>>> sd = machine.SDCard()
>>> sd.info()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OSError: [Errno 116] ETIMEDOUT: ESP_ERR_TIMEOUT
>>> os.mount(sd, "/sd")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
OSError: 16

mosi = GPIO 40 miso = GPIO 38 sck = GPIO 39 cs = ?