When setting up npm in your corporate environment that is behind proxy. Most likely you receive an error like below when installing packages.

npm ERR! request to https://registry.npmjs.org/typescript failed, reason: write EPROTO 101057795:error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol:openssl\ssl\s23_clnt.c:827:

To resolve this issue, we need to execute below commands.

Set HTTP proxy

npm config set http-proxy http://proxy.example.net:80

Set HTTPS proxy

npm config set https-proxy http://proxy.example.net:80

Change registry to http

npm config set registry http://registry.npmjs.org/

Clean NPM cache

npm cache clean --force