You will receive a Disk Image file with suffix .dmg. On finding the file in your Downloads folder, either double-click or right-click-and-select-Open on the file to mount a virtual disk with the installers.
If your system runs Mac OS 10.6 through 10.13, the two installation packages, with suffix .pkg, on the disk window will install the plugin on your system. If your system runs Mac OS 10.14 or higher, either double-click or right-click-and-select-Open the folder icon on the lower left to show the 64-bit only plugin installation packages.
The .pkg file with AU64 will install the Audio Unit plugins. The .pkg file with AAX will install the Pro Tools plugins. Either double-click or right-click-and-select-Open the installation file or files to install the plugins for the appropriate workstations you use.
You will also receive a license string. To generate your license, launch the iLok License Manager application and click on the Redeem Code button to the right of the Search bar. Copy the contents of the license string to the code fields of the pop-up window.