Hello, thank you for reaching out.
It is the Administrator password for the system you used during the initial Windows setup. If you set up Windows with a Microsoft account, use the password you entered the first time during setup. If you used a local account, use the password for that local account.
If you’re having trouble finding the correct password for your account, you’ll need to create a bootable USB installation media and use it to repair Windows. To do this, boot the device from the USB installation media, then select 'Repair your computer' instead of Install Windows. This will take you to the Windows Recovery Environment.
From there, you can open the WinRE Command Prompt, which does not require your administrator password.
You can use the Windows 10 Media Creation Tool to create bootable installation media -
Let me know if you still need more help.