hash key

In macOS, to type a hash we use alt-shift-3. In parallels this does not work in Windows or Linux In Windows you have to use ctrl-alt-3 In Linux, I have not yet found a key alternative. Can we get some unity to this simple usage? Sean

Where is my # key in Windows 10 on my MacBook? I am using macOS X Mojave - 10.14.5. On the Mac side it is available with <Option - right> - 3 Keyboard layout and region: UK Windows 10 sees this combination as something different. Using Win 10 in full screen. Any suggestions?