Hi Sérgio,
Welcome to the Q&A Forum; this is a great place to get support, answers, and tips.
Thank you for posting your question; I'll be more than glad to help you out.
It depends on the version and edition.
If you install just a SQL Server Reporting Service (formerly known as SSRS), you might use the same product key as for your installation.
Re-run the setup process of your SQL Server and copy the product key into the SSRS installation process.
If you are installing the PowerBI Report server, this might not work, as this needs an Enterprise license key.
https://learn.microsoft.com/en-us/power-bi/report-server/find-product-key
I hope my answer is helpful to you,
Your
Bjoern Peters
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