You don't need to buy anything to reinstall Windows 10. Use Microsoft Media Creation Tool to create the installer on a flash drive, boot from that flash drive and begin the installation process. I wrote a detailed description of how to install Windows 10 and 11. It may help you. Here's another description of the install process, from a Microsoft MVP. If this is the older latitude you posted about elsewhere, it would be prudent to run hardware tests on the laptop and drive first. Run Dell Diagnostics:Immediately after pressing the power button to turn on the laptop (or after clicking the Reboot command), press and hold (or repeatedly press) F12 to enter the One Time Boot Menu, select Diagnostics and press Enter. The Dell Diagnostics will test major hardware components. Choose to run the extended tests.
I'm trying to do a fresh install of Windows 10 on a blank Hard Drive on a Latitude.  I have the Windows 10 Media Recovery USB Key, and and am able to boot from it.  But when I try to do a fresh install, it gives the error "Unable to reset your PC.  A required drive partition is missing.
Installing Windows 10 on a Blank Drive