Enter sample TestNav credentials

credentials.sh

# Click full-screen button so all computers have the Safari window in the same position
osascript -e 'tell application "System Events"
set frontmost of process "Safari" to true
tell process "Safari"
click button 4 of window 1
end tell
end tell'

# Sleep for a bit seconds to make sure full screen is fully-activated
sleep 3

# Enter sample credentials
# Again, adjust these coordinates per your device using Cmd+Shift+4
click -x 1200 -y 320

sleep 1

osascript -e 'tell application "System Events"
keystroke "username"
keystroke tab
keystroke "testcode"
keystroke return
end tell'