Want to install a script

How can I install a script on the panel

… are you aware of Please read this, before you start! ?

Also your question is missing a lot of information, it basicly tells “I want to drive”.

It’s a script I purchased from codecanyon I want to install it on a sub domain on my Hestia panel

See the rules:

We assume that you are familiar with the basics of server administration, as well as knowledge about setting up and managing hosting applications. This means we assume that even without Hestia you would be able to set up a LAMP stack and manage your email, but are looking for a tool to simplify these tasks.

Follow the instructions how to do it or contact the developer…