Download and install OS 12 Monterey

I am running 10.14.6 Mohave on a late 2013 MacBook Pro.

I want to download and install Monterey on a connected drive without overwriting 10.14.6.

I want to keep 10.14.6 so that I can continue using Photoshop CS6, which isn't compatible with OS 12.

The problem I am having is finding a downloadable version of 12 without going through the App Store and updating 10.14.6

Anybody have a link for OS 12 Monterey that I can install on the drive?