I'd suggest you use an installer USB drive created on a PC - boot from that and do a clean install of Windows on the internal SSD (wiping it in the process). If you also want MacOS put that on a second (external?) drive. Windows will usually install itself pretty well on a bare Mac but sometimes you have to find drivers for the various bits of hardware. Bootcamp isn't a great source of drivers most are old and may not work with Windows 10.
+
+
=== Update (12/12/2022) ===
+
+
With a separate drive to install Windows there is no need to use BootCamp. Here I have a 2012 MacBook with the Windows USB installer inserted. Holding down the Option key when booting the Mac will allow you to boot from the USB drive and install Windows on any internal SSD or HDD. If you have made the BootCamp disk it may be useful as a source of Windows drivers but you can usually find better ones elsewhere.
I'd suggest you use an installer USB drive created on a PC - boot from that and do a clean install of Windows on the internal SSD (wiping it in the process). If you also want MacOS put that on a second (external?) drive. Windows will usually install itself pretty well on a bare Mac but sometimes you have to find drivers for the various bits of hardware. Bootcamp isn't a great source of drivers most are old and may not work with Windows 10.