ISquishWorms
Indeed we moved WiFi pre-settings into a new file, to allow adding multiple SSIDs. But this was with v6.17 so the image should already contain it.
You found the dietpi-wifi.txt on flashed SDcard beside the dietpi.txt?
Instead of double quotes, use single quotes around SSID and password, then no escaping is required at all, only for the single quote itself: ’ => ‘’’
Within the WiFi settings GUI later, this will as well be done automatically, so no escaping required at all.
If the file does somehow not exist on your image, create it with content:
# WiFi SSID (Case Sensitive)
aWIFI_SSID[0]='MySuperDooperWiFi'
# Key options: If no key (open), leave this blank
aWIFI_KEY[0]='0123456789'
# Available options: NONE (no key/open) | WPA-PSK | WEP | WPA-EAP (then use settings below)
aWIFI_KEYMGR[0]='WPA-PSK'
# WPA-EAP Options
aWIFI_PROTO[0]=''
aWIFI_PAIRWISE[0]=''
aWIFI_AUTH_ALG[0]=''
aWIFI_EAP[0]=''
aWIFI_IDENTITY[0]=''
aWIFI_PASSWORD[0]=''
aWIFI_PHASE1[0]=''
aWIFI_PHASE2[0]=''
# Location of the certificate file (eg: /boot/mycert.cer)
aWIFI_CERT[0]=''