MacOS High Sierra & MacOS High Sierra 10.13.2

Hello,

I've been trying to update my software to macOS High Sierra 10.13.2 (so I can update my zoom account in order to attend meetings), and it's telling me I first need to install macOS High Sierra...

When I attempt to download from the app store, and "open" the app, this is the message that appears...

"This copy of the Install macOS High Sierra application is damaged, and can't be used to install macOS."

without further instructions.

Is there another way I can download High Sierra to then obtain macOS High Sierra 10.13.2?

Thank you