TOML file key/value pairs?

Is there documentation somewhere where I can find out all the possible key/value pairs that can be used in the toml files?

Various Gitub repos are full of these file types all with different settings. I would like to explore and understand what all the key/value pairs can do / mean and possibly leverage them.

I am running Chirpstack out of a docker container…as you can see the chirpstack --help command doesn’t talk share any info with respec to this.…Also interested in the chirpstack-gateway-bridge.toml


I found this link and tried to leverage but to no avail :

My results even after chmod 777 :

chirpstack configfile > /etc/chirpstack.toml

only to get error:
-bash: /etc/chirpstack.toml: Permission denied