An on premise solution is possible, but it will only run for about 2 hours. The same as for your local development on your pc or laptop.
How to run it? Follow the instructions for setting up an on-premise server: like https://docs.mendix.com/howto6/deploy-mendix-on-microsoft-windows.
The only difference between this 'free' version and a production one is that you have not applied a valid license. You can run it manually from the Mendix Service Console or as a Windows Service, but either way, without a valid license it will only run for between one and two hours before shutting down, and the number of logins is restricted.
Unlike the sandbox environment, it will not automatically wake up if someone tries to access it - you need to manually restart the service after it has timed out. On the plus side, I don't believe there is any limit on the database size.
You can run for free with limitations in the Mendix Cloud/Sandbox, there is no on-premise free license.