🖱️ Download & Double‑click
Download the file ONYXBOOT_Mac_Installer.pkg (or .dmg) and double‑click it.
📁 Downloads → ONYXBOOT_Mac_Installer.pkg
↯ Double‑click to start
If macOS says “can’t be opened because it’s from an unidentified developer”, right‑click the file and select Open → then click Open again.