no audio hook up for headphones on tv

Solution
that´s more and more common that no analogue output like for headphones will disappear on the market. If your TV has a digital output you will have to get something like this for your current headphones:
https://www.youtube.com/watch?v=S5ZXjKjNy1I

depending on which digital output your TV has, you will need coax or spdif converter to analogue 3.5"


or if your TV has a built bluetooth, get headphones with bluetooth
that´s more and more common that no analogue output like for headphones will disappear on the market. If your TV has a digital output you will have to get something like this for your current headphones:
https://www.youtube.com/watch?v=S5ZXjKjNy1I

depending on which digital output your TV has, you will need coax or spdif converter to analogue 3.5"


or if your TV has a built bluetooth, get headphones with bluetooth
 
Solution
The digital output on TVs are fixed volume and many DACs don't have volume controls or enough power to drive all headphones so you would need a DAC/Headphone amp if you wanted to use wired headphones.
It is possible to install a headphone jack but it would void the warranty.