When you download a purchased license, you specify the website(s) you wish to use the software on.

If you purchased a license for mysite.com, and try and use it on othersite.com, the software will display the 'unlicensed' message on othersite.com, but not on mysite.com

Similarly, if you purchased a license for mysite.com, and you are testing it on your development website, e.g. mysite.local or localhost, the software will display the 'unlicensed' message on the development websites, but noton mysite.com.

In most cases, it shouldn't matter that the message displays on the development website, as the software's behaviour is not limited or altered.

If you do want to use the software on several live websites, rather than buying single licences, consider a multi-website license as there are significant discounts available.

You can check which websites the software is licensed for by looking at the top of the .js file - there you will see the list of websites.