Download Catalina to install on different iMac
i have a client with a late 2015 iMac running High Sierra. she'd like to upgrade to Catalina but has a really slow internet connection. i tried to download it on my late 2011 iMac (since my internet is 10-20 times faster) to install on her mac but the app store won't let me since my mac is too old to run Catalina. is there a way around this?
iMac 27", macOS 10.13