VDK_Recolt__DynamicBlipsAndIllegalJob

-- server.lua (job system) --

Just add : TriggerClientEvent("recolt:updateJobs", source, job) to update function

function updatejob(player, id)
  local job = id
  MySQL:executeQuery("UPDATE users SET `job`='@value' WHERE identifier = '@identifier'", {['@value'] = job, ['@identifier'] = player})
  TriggerClientEvent("recolt:updateJobs", source, job)
end

-- server.lua (vdk_recolt) --

Here, I add a result variable (because if you run twice the SQL query, there is a weird error ^^') and modify the SQL Query

RegisterServerEvent("jobs:getJobs")

local jobs = {}
local result = nil

AddEventHandler("jobs:getJobs", function ()
	jobs = {}
	if(not result) then
		local executed_query = MySQL:executeQuery("SELECT price, i1.`id` AS raw_id, i1.`libelle` AS raw_item, i2.`id` AS treat_id, i2.`libelle` AS treat_item, p1.x AS fx, p1.y AS fy, p1.z AS fz, p2.x AS tx, p2.y AS ty, p2.z AS tz, p3.x AS sx, p3.y AS sy, p3.z AS sz, job_id FROM recolt LEFT JOIN items i1 ON recolt.`raw_id`=i1.id LEFT JOIN items i2 ON recolt.`treated_id`=i2.id LEFT JOIN coordinates p1 ON recolt.`field_id`=p1.id LEFT JOIN coordinates p2 ON recolt.`treatment_id`=p2.id LEFT JOIN coordinates p3 ON recolt.`seller_id`=p3.id")
		result = MySQL:getResults(executed_query, { 'price', 'raw_id', 'raw_item', 'treat_id', 'treat_item', 'fx', 'fy', 'fz', 'tx', 'ty', 'tz', 'sx', 'sy', 'sz', 'job_id' })
		if (result) then
			jobs = result
		end
	else
		jobs = result
	end
    TriggerClientEvent("cli:getJobs", source, jobs)
end)

-- Your Database --

Create a non-null job exclusive to all illegal jobs (mine is 6 for exemple) and change all illegal harvest job id to this new created ID

-- vdkrec.lua (vdk_recolt) --

Lot of modification, so there the complete file ^^'
NOTE : change item.job_id == 6 by item.job_id == <Your Illegal Job Id> in IsNear function

local recoltDistance = 10
local timeForRecolt = 4000 --1000 for 1 second

local near
local jobId = 1
JOBS = {}
BLIPS = {}

RegisterNetEvent("jobs:getJobs")
RegisterNetEvent("cli:getJobs")
RegisterNetEvent("recolt:updateJobs")

AddEventHandler("recolt:updateJobs", function(id)
    jobId = id
	TriggerServerEvent("jobs:getJobs")
end)

AddEventHandler("playerSpawned", function()
    TriggerServerEvent("jobs:getJobs")
end)

-- Get the list of all jobs in the database and create the blip associated
AddEventHandler("cli:getJobs", function(listJobs)
    JOBS = listJobs

	for k, existingBlip in ipairs(BLIPS) do
        RemoveBlip(existingBlip)
    end

    Citizen.CreateThread(function()
        for _, item in pairs(JOBS) do
			if(item.job_id == jobId) then
				setBlip(item.fx, item.fy, item.fz, 17)
				setBlip(item.tx, item.ty, item.tz, 18)
				setBlip(item.sx, item.sy, item.sz, 19)
			end
        end
    end)
end)

-- Control if the player of is near of a place of job
function IsNear()
    local ply = GetPlayerPed(-1)
    local plyCoords = GetEntityCoords(ply, 0)
	if(IsPedInAnyVehicle(ply, true) == false) then
		for k, item in ipairs(JOBS) do
			if(item.job_id == jobId or item.job_id == 6) then
				local distance_field = GetDistanceBetweenCoords(item.fx, item.fy, item.fz, plyCoords["x"], plyCoords["y"], plyCoords["z"], true)
				local distance_treatment = GetDistanceBetweenCoords(item.tx, item.ty, item.tz, plyCoords["x"], plyCoords["y"], plyCoords["z"], true)
				local distance_seller = GetDistanceBetweenCoords(item.sx, item.sy, item.sz, plyCoords["x"], plyCoords["y"], plyCoords["z"], true)
				if (distance_field <= recoltDistance) then
					--jobId = k
					return 'field', item
				elseif (distance_treatment <= recoltDistance) then
					--jobId = k
					return 'treatment', item
				elseif (distance_seller <= recoltDistance) then
					--jobId = k
					return 'seller', item
				end
			end
		end
	end
end

-- Display the message of recolting/treating/selling and trigger the associated event(s)
function recolt(text, item, rl)
    if (text == 'Récolte') then
        TriggerEvent("mt:missiontext", text .. ' en cours de ~g~' .. tostring(item.raw_item) .. '~s~...', timeForRecolt - 800)
        Citizen.Wait(timeForRecolt - 800)
        TriggerEvent("player:receiveItem", tonumber(item.raw_id), 1)
        TriggerEvent("mt:missiontext", rl .. ' ~g~' .. tostring(item.raw_item) .. '~s~...', 800)
    elseif (text == 'Traitement') then
        TriggerEvent("mt:missiontext", text .. ' en cours de ~g~' .. tostring(item.raw_item) .. '~s~...', timeForRecolt - 800)
        Citizen.Wait(timeForRecolt - 800)
        TriggerEvent("player:looseItem", tonumber(item.raw_id), 1)
        TriggerEvent("player:receiveItem", tonumber(item.treat_id), 1)
        TriggerEvent("mt:missiontext", rl .. ' ~g~' .. tostring(item.treat_item) .. '~s~...', 800)
    elseif (text == 'Vente') then
        TriggerEvent("mt:missiontext", text .. ' en cours de ~g~' .. tostring(item.treat_item) .. '~s~...', timeForRecolt - 800)
        Citizen.Wait(timeForRecolt - 800)
        TriggerEvent("player:sellItem", tonumber(item.treat_id), tonumber(item.price))
        TriggerEvent("mt:missiontext", rl .. ' ~g~' .. tostring(item.treat_item) .. '~s~...', 800)
    end
    Citizen.Wait(800)
end

function setBlip(x, y, z, num)
    local blip = AddBlipForCoord(x, y, z)
    SetBlipSprite(blip, tonumber(num))
    SetBlipAsShortRange(blip, true)
	table.insert(BLIPS, blip)
end

-- Constantly check the position of the player
Citizen.CreateThread(function()
    Citizen.Wait(5000)
    while true do
        Citizen.Wait(1)
        near, item = IsNear()
        if (exports.vdk_inventory:notFull() == true) then
            if (near == 'field') then
                recolt('Récolte', item, '+1')
            elseif (near == 'treatment' and exports.vdk_inventory:getQuantity(item.raw_id) > 0) then
                recolt('Traitement', item, '+1')
            elseif (near == 'seller' and exports.vdk_inventory:getQuantity(item.treat_id) > 0) then
                recolt('Vente', item, '-1')
            end
        else
            if (near == 'treatment' and exports.vdk_inventory:getQuantity(item.raw_id) > 0) then
                recolt('Traitement', item, '+1')
            elseif (near == 'seller' and exports.vdk_inventory:getQuantity(item.treat_id) > 0) then
                recolt('Vente', item, '-1')
            end
        end
    end
end)

function Chat(debugg)
    TriggerEvent("chatMessage", '', { 0, 0x99, 255 }, tostring(debugg))
end

-- Optional : GUI.lua (vdk_inventory < v1.5) --

If you want to prevent adding / remove items in the inventory (it fix also when you have a controller and make bug UI when you run)

Comment line 62 and line 63 :
--elseif IsControlJustPressed(1, Keys["NENTER"])  then
--		MenuCallFunction(Menu.GUI[Menu.selection +1]["func"], Menu.GUI[Menu.selection +1]["args"])