Build Error

I am creating local project , by following instructions in https://adobeio-codelabs-custom-events-adobedocs.project-helix.page/?src=/lessons/lesson4.html

However when i execute

>aio app build , am getting following error

"moduleIdentifier": "C:\\diMonitoring5\\diMonitoring5\\src\\dx-excshell-1\\actions\\slack\\index.js",
» "moduleName": "./src/dx-excshell-1/actions/slack/index.js",
» "loc": "1:14-32",
» "message": "Module not found: Error: Can't resolve 'request' in 'C:\\diMonitoring5\\diMonitoring5\\src\\dx-excshell-1\\actions\\slack'",
» "moduleId": 663,
» "moduleTrace": [],
» "details": "resolve 'request' in 'C:\\diMonitoring5\\diMonitoring5\\src\\dx-excshell-1\\actions\\slack'\n Parsed request is a module\n using descripti