It seems the package @oanda/v20 is not published on npm.
λ npm install @oanda/v20
npm ERR! Windows_NT 10.0.14393
npm ERR! argv "C:\\My\\Programs\\nodejs\\node.exe" "C:\\My\\Programs\\nodejs\\node_modules\\npm\\bin\\npm-cli.js" "install" "@oanda/v20"
npm ERR! node v7.0.0
npm ERR! npm v3.10.8
npm ERR! code E404
npm ERR! 404 Not found : @oanda/v20
npm ERR! 404
npm ERR! 404 '@oanda/v20' is not in the npm registry.
npm ERR! 404 You should bug the author to publish it (or use the name yourself!)
npm ERR! 404
npm ERR! 404 Note that you can also install from a
npm ERR! 404 tarball, folder, http url, or git url.
npm ERR! Please include the following file with any support request:
npm ERR! C:\My\Dev\zzz\oanda-test\npm-debug.log
It seems the package
@oanda/v20
is not published onnpm
.