If everything is set up right, try to log into your Gateway with PuTTY (or something similar) and try to run the single_pkt_fwd script manually. Also if you haven’t already I would suggest looking at all the info on the LG01 on the TTN forum since you’re question isn’t really related to LoRaServer and this forum.
En la configuración del servidor, no te olvides de colocar bien la dirección del servidor, tu id y el correo en el cual estás registrado en el servidor.