How do I change player models?

I’m stumped on why this doesnt work. Im trying to change my player model but nothing happens. I dont get any errors.

Can anyone help me?

ply:SetModel( "models/player/Group01/male_08.mdl" )

i have no idea that is the right code so it wouldn’t have anything to do with the SetModel

Do I need to add a function saying to render the player again?

Where is that code being called from?
It has to be server-side for everyone to see.

like rejax says what file is it being called from

function PlayerSetModel( ply )
    ply:SetModel( "models/player/Group01/male_08.mdl" )

hook.Add( "PlayerSpawn", "PlayerSetModel", PlayerSetModel )

Run this serverside.