npm install returns connection timeout while building docker image

In my case works with this steps:

I added

net.ipv4.ip_forward=1

Give me the IP 104.16.25.38

docker build . --add-host registry.npmjs.org:104.16.25.38 -t test

docker npm node-modules npm-install

In my case works with this below single step,

docker build --add-host registry.npmjs.org:104.16.25.38 -t .

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