How to slow down a server side object client side with vector force

hey so like the title says im trying to do like what this person did but for the client. I have a server-side object but I want with a click of a button it will slow down it for the client but it doesn’t work every time I do it. I don’t care about server client desync or something like that
thank you in advance

this may help you:

it would but its for server-side