Updated node package globally, but the version was not changed.

When I'd have loved to update a node package

I ran below command for updating firebase-tools version.

yarn add global firebase-tools

But version was not changed

Why version was not changed

Because command was wrong.

Correct command is below.

yarn global add firebase-tools

If we put global before add, node package is installed only globally.
If we put global after add, node package is installed globally and locally.
And my firebase-tools version was different from local and global in my pc.
So, the version was not changed (local version had been old one).

Thank you.
I'm sorry for writing in English.
It's for my practice.