npm i rollup-plugin-concatfiles
npm ERR! code ENOVERSIONS
npm ERR! No valid versions available for rollup-plugin-concatfiles
yarn add rollup-plugin-concatfiles
error Received malformed response from registry for "rollup-plugin-concatfiles". The registry may be down.
info Visit https://yarnpkg.com/en/docs/cli/add for documentation about this command.