In 2021, Emby followed the "freemium" app model. You could download the app for free, but playback was limited (often restricted to a minute or two) unless you had a Premiere key or paid a separate small fee for the app itself.
If you are looking for an "Emby Premiere key 2021," it is important to understand how the licensing system works and why you should avoid unofficial "free" keys found online. What is Emby Premiere? emby premiere key 2021