How to install gulp-csso plugin via cmd?

Question

npm

after typing npm install gulp-csso --save-dev
or npm install gulp-csso -D into cmd
, an error occurred
0 info it worked if it ends with ok
1 verbose cli [ 'C:\\Program Files\\nodejs\\ node.exe',
1 verbose cli 'C:\\Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js',
1 verbose cli 'install',
1 verbose cli 'gulp-csso ',
1 verbose cli '-D' ]
2 info using [email protected]
3 info using [email protected]
4 verbose npm-session c594f575e45062d9
5 silly install loadCurrentTree
6 silly install readLocalPackageData
7 silly fetchPackageMetaData error for [email protected] request to https://registry.npmjs.org/gulp-cssofailed, reason: self signed certificate in certificate chain
8 timing stage:rollbackFailedOptional Completed in 3ms
9 timing stage:runTopLevelLifecycles Completed in 555ms
10 verbose type system
11 verbose stack FetchError: request to https://registry.npmjs.org/gulp-csso failed, reason: self signed certificate in certificate chain
11 verbose stack at ClientRequest.req.on.err (C:\Program Files\nodejs\node_modules\npm\node_modules\node-fetch-npm\src\index.js:68: 14)
11 verbose stack at ClientRequest.emit (events.js:182:13)
11 verbose stack at TLSSocket.socketErrorListener (_http_client.js:391:9)
11 verbose stack at TLSSocket.emit (events.js:182:13)
11 verbose stack at emitErrorNT (internal/streams/destroy.js:82:8)
11 verbose stack at emitErrorAndCloseNT (internal/streams/destroy.js:50:3)
11 verbose stack at process._tickCallback (internal/process/next_tick. js:63:19)
12 verbose cwd C:\Users\dertanjan\Desktop\New Folder
13 verbose Windows_NT 10.0.16299
14 verbose argv "C:\\Program Files\\nodejs\\node.exe" "C:\\ Program Files\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "install" "gulp-csso" "-D"
15 verbose node v10.13.0
16 verbose npm v6.4.1
17 error code SELF_SIGNED_CERT_IN_CHAIN
18 error errno SELF_SIGNED_CERT_IN_CHAIN
​​19 error request to https://registry.npmjs.org/gulp-cssofailed, reason: self signed certificate in certificate chain
20 verbose exit [ 1, true ]
please help fix installation