gyp ERR, Npm is unable to get local issuer certificate

I had the same issue. Below solved my problem

set NODE_TLS_REJECT_UNAUTHORIZED=0 Then npm install again

You can refer to: https://github.com/nodejs/node-gyp/issues/695

The answer from @Emon is correct, however for Linuz users the command obviously would be:

export NODE_TLS_REJECT_UNAUTHORIZED=0