lghtroom para Mac OS 10.14.6

I assume that you cannot upgrade your MACOS.

So, LrC v10 or later (older) 

Supported per:

https://helpx.adobe.com/lightroom-classic/system-requirements/2021.html

Current Adobe Creative Cloud Desktop App will only present latest two major versions, i.e. v12 and v12, so not v10.

Hopefully another member has a link for you, otherwise you need to contact Adobe.

(communication thru this community page is not contacting Adobe)