[HELP]Can't get task to work server/ client

FiveM Resource Development Discussion
1

I have an event in my client.lua

on top my of my code:

RegisterNetEvent('fishing:startFishing')

then at the botton:

AddEventHandler("fishing:startFishing", function()
		TaskStartScenarioInPlace(player, "WORLD_HUMAN_STAND_FISHING", 0, false)
		Wait(math.random(3000,5000))
		fishcaught = true
end)

on the server file I have

at top:

RegisterServerEvent('fishing:BeginFishing')

then underneath:

AddEventHandler('fishing:BeginFishing', function()
  TriggerClientEvent('fishing:startFishing', source, function()
  end)
end)

When I press E ingame I get

Can someone tell me what I am doing wrong please?