Used to own a CR10SP. Gave it to my son-in-law when I bought the K2 Plus. I seem to remember the microSD card was on the right side of the printer. I, personally, never used the wifi but I know my son-in-law did, through the cloud I think. I know that jimandyen is correct about it only using 2.4 GHz. It also didn’t like negotiating wireless extenders, which is why I didn’t use the wifi.
The CR-10 Smart Pro has a separate Wi-Fi board. That board contains a microSD card slot. You may need to remove the bottom cover. The card is on the Wi-Fi module.