Applying LUTs to Film:
You can apply your unzipped .CUBE LUT files directly to any clip of film from the Lumetri panel under Basic Correction > Input LUT > Browse...:



Adobe describes this here: https://helpx.adobe.com/premiere-pro/using/looks-and-luts.html

Installing LUTs into Premiere Pro:
Once you have downloaded you LUT files, you can install them into other applications. In Premiere Pro, custom LUT files appear in the Lumetri Color panel.

To install a custom LUT file, create one or more of the directories listed below:

Mac OS:
Available only to the local user:

• /Users/<user_name>/Library/Application Support/Adobe/Common/LUTs/Creative
• /Users/<user_name>/Library/Application Support/Adobe/Common/LUTs/Technical

Available to all users:

• /Library/Application Support/Adobe/Common/LUTs/Creative
• /Library/Application Support/Adobe/Common/LUTs/Technical

Copy your custom LUT files to the respective folder.
When you launch a project using Premiere Pro, these folders are scanned and LUT files are loaded from these directories. LUTs in the Creative directories appear in the Creative Looks dropdown, and LUTs in the Technical directories appear in the Input LUT dropdowns.