Error while installing a plugin called serverless-stage-manager

While trying to install the serverless-stage-manager plugin via our code pipeline for deployment getting an error
npm ERR! code E401
npm ERR! Unable to authenticate, need: Basic realm=“Artifactory Realm”

command using: serverless plugin install --name serverless-stage-manager --stage {ENV} --region {REGION}

Serverless versions tried: 2.10.0, 3.33.0

Node version -12

It was working smoothly before, getting this issue recently