npm download version of package 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