What is the default value/settings of chirpstack-network-server.toml if a directive is not set yet? For example, rx2_dr and rx2_frequency.
it depends from configured LoRaWAN band.
But default value is -1
Pls. read the parameter description inside chirpstack-network-server.toml file.
https://www.chirpstack.io/network-server/install/config/ contains all the defaults. You can also use
chirpstack-network-server configfile but there is the risk that a config file already exists in which case it will first load your configuration and then print a new configfile with your config merged in.