aloranx2: QUİCK ACSESS WONT WORK ICANT USE MY CROSSBOW AND IN KEYBINDIGS MENU NO CROSSBOW SHORTCUT
I had the same problem but it turns out a the beginning of the game you don't actually have a crossbow. I didn't get one until Vesimir gave me one before battling the griffon, and never found any along the way in my travels nor at any shops so I don't know if you can even have one until Vesimir gives you one. But ... I
thought I had a crossbow because on the Inventory screen it
looks like I had one, but it turns out if you hold your mouse over the slot it says "Empty". It turned out to just be misleading graphics which look like a crossbow but should instead be a greyed-out version for empty slots otherwise it's easy to be tricked into thinking you have one.
Once i actually got a crossbow I was able to select and use it with the TAB key and middle mouse button though, but having a single hotkey to select it would be more PC gamer friendly and less consolitisy.