Default How to connect external hard drive to my Z Ultra

I was trying to connect my 1TB external hard drive to my Z Ultra using the USB OTG, but I keep getting this message:
"USB storage empty or file system not supported"

Any way I could connect it without rooting the phone?

If it's impossible then please give me a link of the fastest way to root my phone (v 4.3 build number 14.2.A.1.136)


Thanks


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