Make LoRaWAN network public via chirpstack

Hello all,

one of our customers would like to make their LoRaWAN network, which we built and runs over Chirpstack, public so that the citizens of the city can use this network. What needs to be done for this? I read about a packet broker via TTN.
Otherwise, is it sufficient to configure another data destination to the public TTN in the Mikrotik gateways used (LtAP LR8 kit as well as wAP)?

I am very pleased about answers. Many thanks in advance!