Question about WD Elements Portable

Is there one that I can use for both systems without having to format it?

If you already have data on it and want to use it on both Mac and Windows without reformatting it to exFAT, the only solution is to install a third-party NTFS driver on your Mac (such as Paragon NTFS for Mac or Mounty). By default, macOS can read Windows NTFS but blocks writing; with this type of utility, you can read and write on both systems directly without changing the original format.

To be able to use a hard drive like this on Mac and Windows at the same time, you must format it in exFAT format.