USB-C OTG Cable/Connector Wiring
Per the USB-C spec, 5.1K to ground on each CC line.
For a discussion of what you need to do and what can go wrong, see the followup to the failure modes of the Raspberry Pi 4:  https://hackaday.com/2019/07/16/exploring-the-raspberry-pi-4-usb-c-issue-in-depth/