Are you accessing the hosted Web API using your application from "http://localhost:8100"? Please advise. In this case you need to add the URL to the CORS section. Please refer to the URL:
https://docs.microsoft.com/en-us/aspnet/web-api/overview/security/enabling-cross-origin-requests-in-web-api
Sample Code for ASP.net Core just for reference
public void ConfigureServices( IServiceCollection services)
{
services.AddMvc();
services.AddCors( options = > {
options.AddPolicy("DemoCorsPolicy", c = > c.WithOrigins("http://localhost:8100"));
});
}
public void Configure( IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory)
{
app.UseMvc();
app.UseCors("DemoCorsPolicy");
}