I'm trying to connect to wifi using latest stable version. The WPA supplicant file doesn't exist and is blank when I bring it up to edit.
Are you using the latest RPi image? or cloud client 5.9.10? You need to get the latest RPi image, not just the cloud client.
Hey, please download the latest image for Raspberry Pi here: https://cloud.3dprinteros.com/download/and follow the native Raspberry Pi WiFi setup guide: https://www.raspberrypi.org/documentation/configuration/wireless/wireless-cli.md
For enterprise and educational licenses there is also 3DPrinterOS Fleet Management software, which allows you to propagate WiFi settings (and much more) on all machines at once.