Intro I had written Angular app and ASP.NET Core app separately. But because I had had to use some internal api at my work, I tried to integrate them. Prepare Angular (CLI ver. 8.3.21) ASP.NET Core (ver. 3.1.101) Because Microsoft.AspNetCore.SpaServices of ASP.NET Core had been obsoleted and changed to Microsoft.AspNetCore.SpaServices.Extensions. So there hadn't been so much documents. [Announcement] Obsoleting Microsoft.AspNetCore.SpaServices and Microsoft.AspNetCore.NodeServices #12890 Thus, I had generated sample program of Angular template. And I had followed it to integrate apps. dotnet new angular -n AngularSample Change Angular app Because of Microsoft.AspNetCore.SpaServices.Extensions, I hadn't needed changing the Angular app. Output Path The output path hadn't been same as Angular template's one. angular.json (Angular CLI) ... "outputPath": "dist/{PROJECT-NAME}", ... angular.json (ASP.NET Core) ... "outputPath...