Navigate to the /bin folder and start the application from the terminal.
On Windows, typically run
Host.exe, and on Linux/Mac run
This should start the application, and the following should be written to the terminal:
> Host.hx:4: Hello from Cppia Host
> Script.hx:4: Hello from Cppia SCRIPT
This indicates that the host has run (traced its own message) and executed the script (traced the script message).
If you get the following message, the host can't find the script file:
> Error: [file_contents,./script.cppia]
Make sure that you have followed the Creating a cppia script tutorial, and that the script.cppia is placed in the same folder as your Host executable.