PvP Controls are explained during the tutorial and are usually also shown again in the PvP loading screen, as shown in the picture below. At the moment they are not customizable, but in future updates it will be possible to change the predefined keys.
In particular, the controls are summarized in the table below:
|Ctrl||Crouch (Keep pressing)|
|F||Drop or Pick up a Weapon from the floow|
|C||Crouch / Stand up|
|B or 1,2,3,4||Swap weapon|
|Left button (Mouse)||Fire|
|Right button (Mouse)||Aim (Sniper weapon)|