Subdoamin categories Post

Subdoamin categories Post, then url generate Like this
“https://www.competitionmantra.com/en/gk/optical-instruments-lens-camera-microscope-telescope/” and i want to Url Like
“https://gk.competitionmantra.com/en/gk/optical-instruments-lens-camera-microscope-telescope/”.
This can’t possibly be as difficult as I’m making it.

Thanks you for any help.

Tej Prakash

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