Turn on PVP in Grief prevention plugin

Hello Aternos, i just wanted to ask that i have GP (grief prevention) installed in my server, can i enable pvp in the claimed lands? My server is kinda big and alot of places are occupied and it's so annoying not being able to fight. Is there any way to turn on PVP while using the GP plugin?

Regards

Haider.

can you tell me where exactly? I'd really appreciate.