I already tried and it don’t work.

Notifications stay on the screen. I think it’s because “0xDD6CB2CCE7C2735C” is very particular function. For example, with basic notification, it’s not possible to have the same message two times but with it, it’s possible.

Edit :
I found with your idea, thanks :

local Notif = {}
RegisterNetEvent("hud:NotifKey")
AddEventHandler("hud:NotifKey", function(icon,text)
    Citizen.CreateThread(function()
        Wait(1)
        SetNotificationTextEntry("STRING")
        local Notification = Citizen.InvokeNative(0xDD6CB2CCE7C2735C,1,icon,text)
        table.insert(Notif,Notification)
    end)
end)

RegisterNetEvent('hud:NotifDel')
AddEventHandler('hud:NotifDel', function()
    for a,v in pairs(Notif) do
        RemoveNotification(v)
    end
   Notif = {}
end)