Song Pro (or Sealion 5) SD card slot missing?

I recently got my Song Pro. It has the DVR hardware (camera at the front windshield, around the rearview mirror), but there is no card slot among the slots under the central console (only USB-C, USB-A and 12V outlet). Where can it be? I've read of other users using a card reader or USB drive on the existing USB, is it confirmed to work? Also, any links for good AliExpress sellers for sdcard or USB drives? Thanks!