Alex unplugged everything. But the story was already written — and he was just reading it. If you actually need a legitimate macOS installer (like High Sierra 10.13.6 or Catalina 10.15.7), let me know and I’ll point you to official Apple support links.
He double-clicked.
Instead, here’s a short story based on your request: Macos High Sierra 10.15.7 Download HOT-