I made the wrong choice

I bought the horse "Celestial Steed" but for the wrong character, how can I reset it?

Open an item misbuy ticket on website here: https://www.warmane.com/account/support?do=new

I don't understand how it works line

<Item selection

Ctrl+click to select multiple items.>
kindly help

"Gold, mounts, upgrades, features, consumables, transmogs

None are refundable, exchangeable or reversible, our policy on consumable refunding or feature reverting (i.e. recustomize, level 80/85) is very strict. "

So you are stuck with it. Maybe there is a chance if it's still in your bag as an item, but then you would have it there to select.