'rollup' is not recognized as an internal or external command

I would like to ask if how should I fix this issue because I am already stuck and confused about this part. I already installed rollup globally using this command

npm install --global rollup

However when I tried to run the 'rollup' command then I should expect the rollup information or something will show in my CLI? but my CLI shows

'rollup' is not recognized as an internal or external command, operable program or batch file.

What I have done so far is.

1. Updated the NPM
2. Reinstall the rollup globally.

I already read some documentation but the issue is still showing.https://github.com/Esri/ago-assistant/issues/176

Please enlighten me. Thank you

What I just have done just to run the script globally.

I just added these scripts in my package.json to run the rollup using NPM.

 "scripts": {
"rollup": "rollup" 

is this okay?