No binary created by compile

I’m new to ESPHome, and honestly struggling with how it hangs together,

Just trying to compile using the command line - yaml based on this GitHub - JNSwanson/ESP-Home-iBoost: ESPHOME Marlec iboost integration

I simply run esphome compile iboost.yaml (I renamed the yaml) - I get a message saying compile successful, but no bin file is produced.

With no bin, when I trry to go to ESPhome web to install, I can;t do anything, as it asks for a bin!

pretty sure I’m missing something, and as a Software developer, I can usually debug stuff, but I would expect a successful compile to produce something