Do I have to buy a Windows license?

I just installed a new SSD in the laptop and booted Windows from a USB stick. Everything worked so far.
But I'm not quite sure whether I still need a Windows Product Key and have to enter it, or whether Windows is already activated?

No is already activated

Has an active Windows 10 Home license

Doesn't it say that it has already been activated and below how it was activated?

Must be activated.

If Win10 has already been installed and activated on the laptop, the product key no longer needs to be entered.

If you come to the "Activate Windows" window during the installation, simply click on "I do not have a product key". - Then it goes on…

Activation takes place automatically, at the latest with the first Windows update.

Thanks!