Make sure Docker is running on Linux containers by right-clicking the Docker icon on the System Tray:
If the button reads Switch to Windows Containers it means you’re already running on Linux Containers.
Create a Dockerfile inside salesdemo_cloud_Installer folder with the following contents:
FROM nginx:1.23.1 WORKDIR /usr/share/nginx/html COPY . . EXPOSE 80
Make sure the file is inside the folder alongside the extracted contents of the ZIP file like this: