Create Balena OS Container

I want to create a balena os container. I have an application and its config file. This application listen a UDP port and gets data and transmits to another balena container locally another port. There may be a network issue on balena side. I have a working version but i dont know how to create a balena os container. I need someone to help me and teach me how to create balena container and how to get balena image of a container. When we create balena container i want to start this application automatically. and never stoppped.