You can downgrade, here are some steps on how to do this:
Insert the USB flash drive in your Windows 11 PC and disconnect any other nonessential USB devices; then go to https://aka.ms/downloadwindows10.
Under the heading "Create Windows 10 installation media," click Download Tool Now.
Run the Media Creation Tool Installer and follow the prompts to create bootable Windows 10 installation media using your USB flash drive. Leave the drive attached to your Windows 11 PC.
Go to Settings > System > Recovery and, under the Advanced Startup heading, click Restart Now.
At the Windows 11 recovery menu, choose Use A Device and select your USB drive. When you see the prompt to boot from the USB drive, tap the spacebar to start Windows Setup.
Follow the prompts to install Windows 10. When you reach the step where you're asked to enter a product key, click I Don't Have A Product Key and then be certain to choose the edition (Home or Pro) that you're "downgrading" from.
When the installation is complete, you should boot into Windows 10, and the operating system should activate automatically. You'll need to install the latest updates, and you might need to download some drivers from the PC maker's website.
Once you've restored your data files and reinstalled any apps, you can get back to work.