Turris mox and gpio led

Hy,
For my project, i need to use the 4 GPIO attributed for led (17-18-19-20).

I have tried with bash by using :

echo "17" > /sys/class/gpio/export 
echo "1" > /sys/class/gpio/gpio23/value

For the first line i have an error :

bash: echo: write error: Invalid argument

and another error for the second line :frowning: