Chrome, CORS and .NET CORE
Most of this information came from https://stackoverflow.com/questions/53479946/how-to-handle-option-header-in-dot-net-core-web-api Getting a cross-origin resource working with Javascript and .NET core should be a simple task but if you're hosting it on IIS, there's an extra step. Instructions for setting up CORS in .NET CORE are all over the place so I'm just going to post an image of what it should look like. The real trick is with IIS. You need to add a Request Filter to allow the OPTIONS verb.