Open your `DevExtremeSample.Web` project folder with a command line and run the `gulp` command. This command will copy the needed library files into the ``/wwwroot/libs/devextreme/` folder.
Open your `DevExtremeSample.Web` project folder with a command line and run the `abp install-libs` command. This command will copy the needed library files into the ``/wwwroot/libs/devextreme/` folder.