To add an activation to Octoplus FRP Tool, please perform the following steps:

Connect your box to PC

Install the latest version of Octoplus FRP Tool software

Open a folder where Octoplus FRP Tool software has been installed

Run a file: updater.exe (inside Octoplus FRP Tool software folder)

Choose "I have the activation code" and press "Next"

Complete update procedure with the activation code that you've received