How would I get this animation to play in a serverscript?

This script listens for an event whenever the player presses any of the WASD keys. However I'm having trouble getting the animation to fire. I understand that player needs to be indexed somewhere but I'm not sure how.If anyone can help me out I'd be grateful.

--Player Values and walking animations--

    local already_ran = false
    local grounded = false
    local idleAnimation = Instance.new("Animation")
    idleAnimation.AnimationId = "rbxassetid://356344446"
    local Left = Instance.new("Animation")
    Left.AnimationId = "rbxassetid://356869859"
    local Right = Instance.new("Animation")
    Right.AnimationId = "rbxassetid://356869859"
	local Forward = Instance.new("Animation")
    Right.AnimationId = "rbxassetid://312976450"
 	local Backward = Instance.new("Animation")
    Right.AnimationId = "rbxassetid://312976450"
    local Jump = Instance.new("Animation")
    Jump.AnimationId = "rbxassetid://326922088"

      function playAnimation(parent) 
        local AnimTrack = player.Character.Humanoid.Animator:LoadAnimation(parent) -- The issue
        AnimTrack:Stop()
        wait(.01)
        AnimTrack:Play()
		print("played anim")
    end
  
	 
	 function onGround(speed)
        if grounded == false then
            grounded = true

local event = game.ReplicatedStorage:WaitForChild("MovementLeftEvent") 
event.OnServerEvent:connect(function(player) 
	
        if speed > 1  then
            if already_ran == false  then
                already_ran = true
                playAnimation(Left)
				print("Left")
				
  local event2 = game.ReplicatedStorage:WaitForChild("MovementRightEvent") 
event2.OnServerEvent:connect(function(player) 
	
        if speed > 1  then
            if already_ran == false  then
                already_ran = true
                playAnimation(Right)
				print("Right")
            
local event3 = game.ReplicatedStorage:WaitForChild("MovementForwardEvent") 
event3.OnServerEvent:connect(function(player) 
	
        if speed > 1  then
            if already_ran == false  then
                already_ran = true
                playAnimation(Forward)
				print("Forward")
            
local event4 = game.ReplicatedStorage:WaitForChild("MovementBackwardEvent") 
event4.OnServerEvent:connect(function(player) 
	
        if speed > 1  then
            if already_ran == false  then
                already_ran = true
                playAnimation(Backward)
				print("Backward")
            


          
        elseif speed > 0 and already_ran == true then
            already_ran = false
            playAnimation(idleAnimation)

	 player.Character.Humanoid.Running:connect(onGround) 
	

        end
    end
end)
end
end
end)
end
end
end)
end
end
end)
end
	end