raspberry TTL printer USB not able to connect

I was following these installation instruction about configuring a TTL Thremal printer in USB.

Thus when I try : echo -e "This is a test.\\n\\n\\n" > /dev/ttyUSB0 it gives me a bash: no permission. I tried using sudo mode : it gaves me the same result

Any idea why ?

Thanks in advance

[edit]

Posted on Raspberry Pie StackExchange

Use

echo -e "This is a test.\\n\\n\\n" > /dev/usb/lp0

you also must do: sudo gpasswd -a <YOUR USERNAME> lp

instead of

echo -e "This is a test.\\n\\n\\n" > /dev/ttyUSB0

This took hours for me to figure out, full credit to this guide: https://www.theamplituhedron.com/articles/How-to-use-a-tiny-thermal-printer-with-Raspberry-Pi/