When you're on the screen that asks you to sign in with a Microsoft account, press: Shift + F10
In the Command Prompt, type the following command exactly: OOBE\BYPASSNRO
The PC will restart automatically.
After rebooting, you will now see the option to "I don’t have internet" or "Continue with limited setup".
Select that, and you'll be able to create a local account, without needing a Microsoft account.