Is it possible to change the gravity of a client while playing?

Hello, i’m trying to program a simple game with my brother. The game would be multiplayer and we would like to be able to change the gravity of the character with the mouse wheel. So i made this code where mouse wheel up and down change the gravity. My problem is than this is working perfectly on the server but isn’t on the client. I shearch a lot but haven’t found anything.
Thanks.

Thanks for the quick answer ! But i shearch a lot on the replication and i still confused : if i replicate these value, when the server will change the gravity, will the client be affected ? because this is not what i wanted. Plus what exactly do i have to replicate ? I’m sorry if its dumb questions ^^

you need replicate these value. check Networking and Multiplayer | Unreal Engine Documentation for detail.