Go to Rockauto.com
Order
Pay for it
And wait til you get it
Then install
If you need to then look up how to do it on youtube
You still need an ignition key to take old lock out
Otherwise call a locksmith
Cost of DIY will be around $200 dollars.
Cost of locksmith will be much much more.
I was able to locate the genuine OEM Hyundai replacement blank key based on your model. You will have to verify fitment based on your VIN to make sure it matches your vehicle. Look around with different locksmiths to see how much they'll charge you to cut the key. Here's the blank key https://www.hyundaipartsdeal.com/genuine/hyundai-key-blanking~81996-29000.html and I hope this helps.