Can't get 'My Passport Ultra' to work on Parallels or Bootcamp


So I have this external storage for my Windows partition however I cannot save files onto it!!!

I am currently on my parallels Windows account and every time I try to save a project onto it, it keeps saying I need permission to perform this action, even though I am the administrator.

Does anyone know how I can resolve this issue? 

A drive formatted NTFS for Windows is read only on a Mac. There is software to make it work but I don’t think it is freeware for this any more.