Error on Mac / Linux : Zsh: command not found nicovideo-dl

It looks like you are trying to run a command that your system cannot find. This can happen for a few reasons:

You might have mistyped the command name. Make sure you are typing the command correctly and that it is spelled correctly.

The command might be located in a different directory than the one you are currently in. In this case, you will need to specify the full path to the command or add the directory where the command is located to your PATH environment variable.

The command you are trying to run might not be installed on your system. In this case, you will need to install the command before you can use it. Try this command:

Brew install nicovideo-dl

How to Fix Zsh Command Not Found Error on macOS?

Other errors on Mac / Linux :

Zsh: command not found nicovideo-dl