Finding and installing an old version of Apple Configurator is a common task for IT admins and vintage tech enthusiasts who need to manage older iOS devices or run the software on legacy Macs that don't support the latest macOS updates. Apple Support Community Why You Might Need an Older Version Operating System Compatibility:

While Apple Configurator generally supports older iOS versions, older builds of the app may be preferred when managing obsolete devices like the first-generation iPad Air.

💡 : If the App Store won't let you download it because you never "bought" it, log into a newer Mac with your Apple ID, "Get" the app there, then return to your old Mac to find it in your purchase history. Are you trying to manage a specific legacy device model?