From opening the app to finding your finished file — here's the whole path, in order.
The first time you open HappyRec, it walks you through three permissions: Screen Recording, Microphone, and an optional Camera. Screen Recording and Microphone are required before the Record button will work; Camera is only needed if you plan to use the Face Cam bubble or an Avatar.
At the top of the main window, choose one of four modes:
Quality (720p/1080p/4K) and frame rate (30/60fps) live in Preferences, along with whether system audio (the sound your Mac is playing) gets captured alongside your mic.
Turn on Camera bubble to appear as a live Face Cam, or switch to an Avatar for an animated character that mirrors your expressions without ever recording your actual face. Both are draggable and resizable, and get burned directly into the video — so they show up even in Window and Area recordings, where a floating overlay window normally couldn't be captured.
Click the blue record button (or ⌘⇧R). A short countdown gives you time to get in position, then recording starts — pause and resume any time with ⌘⇧P.
Finished recordings appear immediately in the Recent Recordings list on the main window, and are saved to ~/Movies/HappyRec by default (changeable in Preferences → Recording). From that list you can play, reveal in Finder, or delete any recording.