Sign in to your product account and use the Download Pro button. Use the ZIP supplied by your account rather than a file from an unofficial download site.

Make sure the free Online Active Users plugin is installed and active first.

1. In WordPress, go to Plugins → Add New Plugin → Upload Plugin.
2. Select your Pro ZIP and choose Install Now.
3. Activate the Pro add-on.

Copy your key from My License in your product account. In WordPress, open Users → Online Active Users → License & Plan, paste the key and activate it.

Keep the key private. Hide it before sharing a screenshot or a support recording.