I am trying to integrate npm's application insights module (https://www.npmjs.com/package/applicationinsights) into my React js application.
My source for doing this is:
import appInsights from 'applicationinsights';
"Fetch API cannot load https://dc.services.visualstudio.com/v2/track.
Request header field content-encoding is not allowed by
Access-Control-Allow-Headers in preflight response."
Please try to use ApplicationInsights-JS.
Additionally, you can refer to https://azure.microsoft.com/en-us/documentation/articles/app-insights-web-track-usage/ for more info.