tlmgr-option
TeX Live settings manager.
TLDR
List all TeX Live settings
$ tlmgr option showall
List all currently set Tex Live settings
$ tlmgr option show
Print all TeX Live settings in JSON format
$ tlmgr option showall --json
Show the value of a specific TeX Live setting
$ tlmgr option [setting]
Modify the value of a specific TeX Live setting
$ tlmgr option [setting] [value]
Set TeX Live to get future updates from the internet after installing from DVD
$ tlmgr option [repository] [https://mirror.ctan.org/systems/texlive/tlnet]