Accidently Wiped Internal Stoareg from my HTC One S - TWRP Shows no OS Found

Hi,
I have accidentally wiped the internal storage on my HTC One S and now when i boot phone TWRP shows no OS installed.
My phone does not has SD card. It uses internal storage so i don't know how to copy the files and install the ROM.

I tried fastboot and adb devices commands but it returns empty. I am a newbie in device rooting so i am not sure where to go from there. I appreciate your help in this matter
Can you please assist me in this matter.

Thanks