How do I install Plesk on an active Linode?

You'll need to install Plesk via the command line interface. Once you've connected, you can follow the below instructions from Plesk's website.

Download Plesk installer:
wget https://autoinstall.plesk.com/plesk-installer

Add proper permissions to Plesk installer:
chmod +x plesk-installer

Run Plesk installer via command line:
./plesk-installer
or
./plesk-installer --all-versions

Follow the terminal prompts. Once the installation is complete, you can follow the instructions in our guide in order to get started after deployment.

I hope this is helpful!