How to change the Plesk Onyx activation code:
You have cloned a server on which Plesk Onyx is installed.
You have installed a server using an image that includes Plesk Onyx.
You have activated port 8443 in the firewall policy that is assigned to the server.
You have already configured Plesk Onyx.
You have logged in to your Cloud Panel.
You are in the Infrastructure > Servers section.
Activate the desired server.
In the Functions section, click Plesk Onyx (Unlimited Domains).
Write down the Plesk Onyx activation code.
Click the URL displayed next to Admin area.
The message This is not a secure connection appears.
Click Go to YOUR IP ADDRESS (insecure).
In the Interface Language list, select English (United States).
Log in to Plesk Onyx as an administrator.
In the left navigation bar, click Tools & Settings.
Click License Management in the Plesk section.
On the Plesk License Key tab, click Install Key.
Enter the activation code.
The Plesk Onyx license key has now been updated.