Copilot feature in Word „Describe what you'd like Copilot to write", does anyone know that?

I saw this copilot feature in Word. It is located between the document and the ribbon. It has the default text "Describe what you'd like Copilot to write".

It's good to see here:

https://youtu.be/QNU_Gbo9qhU?si=S7C52DayNeFBb3Xq 

Is there a source for when and how the feature is available?

Thank you very much for your answers, which I very much appreciate.