Hi Sravana,
You can keep plugin license active only on one WordPress site at a time.
So, you can either deactivate the plugin on production whenever you want to use it on test. But, we won’t recommend you to do that as it will affect production users.
For your case, we will provide you discount considering it’s your 2nd license and also you are going to use it for testing purpose.
Let me know if you want me to send estimates.