how to downgrade a package in npm code example

Example 1: downgrade npm package to specific version

npm install -g npm@version-no

Example 2: npm downgrade package

npm view <package> versions // lets see what versions of package are available
npm install <package>@<version> // install desired version. Remember about flags which maybe you want to use (eg. -g for global)

// example for package 'express'
npm install express@4.17.1