If you have an active subscription, the Toolbox app allows you to install any version. However, the activation uses your current credentials. PhpStorm 2017 will accept your modern JetBrains account login because the licensing backend is backward compatible (usually).
In 2017, JetBrains still provided offline activation codes for users without consistent internet access. Activation Code Phpstorm 2017
If you encounter issues during the activation process, here are some troubleshooting steps: If you have an active subscription, the Toolbox
. Perpetual licenses allow you to use the version that was current when your subscription ended. : If you don't have a code, you can start a 30-day free trial to test the software features. Student/Teacher Licenses If you have an active subscription