my macOs high sierra 10.13 version can I update to mojave 10.14

Delete "Install macOS Mojave" from the Applications folder. You can try the download from this page from Safari but last time I checked the link wasn't working.

How to get old versions of macOS - Apple Support

I have macOs High Sierra 10.13.6 on a late 2015 desktop and I need to update the operating system but the install Mojave app that I have on my computer gives an error saying it is damaged so it can not open. Where can I get Mojave 10.14 to download - I can not find it in the App Store or on apples website? Thanks

not on a Mac 2011 or earlier.