how do i script a button to give a player a weapon?

Put a ClickDetector into the part you want to be clicked. put the weapon you want to give into the ServerStorage

Part = script.Parent -- defines the part

Part.ClickDetector.MouseClick:connect(function(Clicker) -- start event when part is clicked
    local HasWeapon = Clicker.Backpack:FindFirstChild('WeaponName') -- looks for already existing weapon
    if not HasWeapon then -- prevents from getting more than one
    local Clone = game.ServerStorage.WeaponName:Clone() -- duplicates the weapon
    Clone.Parent = Clicker.Backpack -- puts weapon into player's backpack
    end
end)