tftpd on xinetd, not able to serve files Error `tftpd: unknown option -?`

I'm trying to serve a connection of tftpd (using xinetd) and I'm getting this error

$ sudo systemctl status xinetd
"tftpd[18566]: unknown option -?"

After establishing the connection from a the remote host, When attempting to get a file (or any other action) . I dont know what may be wrong as I setted all the permissions and everything according to the tutorial

sudo apt-get install xinetd tftpd tftp
sudo mkdir -p /etc/xinetd.d/
sudo touch /etc/xinetd.d/tftp

sudo vim /etc/xinetd.d/tftp
##copy the text below
service tftp
{
protocol = udp
port = 69
socket_type = dgram
wait = yes
user = nobody
server = /usr/sbin/in.tftpd
server_args = /srv/tftp
disable = no
}


sudo mkdir /srv/tftpd
sudo cp ~/Downloads/openwrt-18.06.1-ar71xx-generic-wndr3800-squashfs-factory.img /srv/tftp
sudo chmod -R 777 /srv/tftp
sudo chown -R nobody /srv/tftp
sudo systemctl restart xinetd.service