TTN Arduino Library

Good afternoon, I am using the TTN library for thethings one and I have the doubt, is it possible to change the communication channel to be able to connect several devices with the same library or does the port change automatically?

I am using this library …

Like all LoRaWAN networks, TTN supports many devices at the same time, sharing a limited number of radio channels and somewhat independent coding schemes primarily by relying on nodes only being actively transmitting a tiny fraction of the time.

Nodes need a unique identity to be told apart, not unique frequencies or software or application ports.