Revoice Pro 4 activation and installation are two parallel, independent procedures.
It is essential to complete both procedures; the order is not relevant.
Please follow these steps very carefully:
using your internet browser and click the "Create Free Account" button:

Enter your details in the "Free Account Setup" page:

Choose your desired options,
tick the checkbox to accept the Terms of Use,
and click the green "Create Account" button:
The License Support Installer includes the necessary iLok drivers
and iLok Licence Manager software, which you will need to manage all your iLok licenses.
Run the installer and launch iLok License Manager software...

... then click "Sign in" to enter your User ID and Password that you chose when you created your iLok account:
... choose Licenses > Redeem Activation Code...

... and enter your Activation Code in the window that will appear:

(You can copy the Activation Code from your confirmation email and paste it onto this window)
Your iLok License will be deposited in your iLok account
and it will become visible in iLok Licence Manager software:

Now, to complete your license activation, you have two options: either...
Drag and drop your Revoice Pro 4 license to your iLok 2 or iLok 3 USB key:

... or...
Open an iLok Cloud session by choosing File > Open Your Cloud Session:
from the Synchro Arts Downloads page at https://www.synchroarts.com/downloads/
The software installer is the same for full and trial licenses.
(You can also download the Revoice Pro 4 User Manual from this page.)
If you have already obtained your trial license, you want to click the blue button in the LATEST VERSION section:
On a macOS system, open the .dmg file and drag the Revoice Pro application icon onto the alias for the Applications folder:

On a macOS system, to install the Revoice Pro AAX, Audio Units and VST3/ARA plug-ins, please launch the standalone application once, while your DAW is not running.
On a Windows system, just run the Revoice Pro 4 installer - it will install Revoice Pro 4 software and its plug-ins.
It is essential to complete both procedures; the order is not relevant.
Please follow these steps very carefully:
Activation
If you haven't got an iLok account yet, please visit www.ilok.comusing your internet browser and click the "Create Free Account" button:

Enter your details in the "Free Account Setup" page:

Choose your desired options,
tick the checkbox to accept the Terms of Use,
and click the green "Create Account" button:

Now you can download the latest iLok License Support Installer for your OS from www.ilok.com:
The License Support Installer includes the necessary iLok drivers
and iLok Licence Manager software, which you will need to manage all your iLok licenses.
Run the installer and launch iLok License Manager software...

... then click "Sign in" to enter your User ID and Password that you chose when you created your iLok account:
... choose Licenses > Redeem Activation Code...

... and enter your Activation Code in the window that will appear:

(You can copy the Activation Code from your confirmation email and paste it onto this window)
Your iLok License will be deposited in your iLok account
and it will become visible in iLok Licence Manager software:

Now, to complete your license activation, you have two options: either...
Drag and drop your Revoice Pro 4 license to your iLok 2 or iLok 3 USB key:

... or...
Open an iLok Cloud session by choosing File > Open Your Cloud Session:
Installation
Download the latest Revoice Pro 4 software installer for your Operating Systemfrom the Synchro Arts Downloads page at https://www.synchroarts.com/downloads/
The software installer is the same for full and trial licenses.
(You can also download the Revoice Pro 4 User Manual from this page.)
If you have already obtained your trial license, you want to click the blue button in the LATEST VERSION section:
On a macOS system, open the .dmg file and drag the Revoice Pro application icon onto the alias for the Applications folder:

On a macOS system, to install the Revoice Pro AAX, Audio Units and VST3/ARA plug-ins, please launch the standalone application once, while your DAW is not running.
On a Windows system, just run the Revoice Pro 4 installer - it will install Revoice Pro 4 software and its plug-ins.