If you're concerned about installation disc, then you can use the ISO files instead which are available free from Microsoft at:
https://www.microsoft.com/software-download/windows11
You can create Windows 11 installation media directly using Media Creation Tool from Microsoft.
Alternatively, you can download ISO file and create a bootable USB to clean install on any device, any time without any cost. Note, that you've to only buy the license key to activate a clean install.
Note: Included links in this reply refers to blog posts by a trusted Microsoft MVP.