Can't Target certain pages? Facebook Ads

As the title says. Why is that I can't target certain pages when I am making an AD and choosing an audience? For example, I have a product related to the game Playersunknown Battlegrounds. I can target everything similar to Playersunknown Battlegrounds but not Playersunknown Battlegrounds itself. In fact it does not even pop up as a option when making my ad? Could someone explain why this is or is there way around this? Ive notice this for other pages as well

Thanks In Advance
- Rob

there must be a part where you can add a custom keyword to show your advert...

unless there no custom choice ,and only can choose what shown in there list.

surely there should be a auto update of the keywords used and allow advert users to send advert to....