At the first you need to ensure Topx Notify before qb-core script then you can replace this function you will find it in
qb-core/client/functions.lua
function QBCore.Functions.Notify(text, textype, length)
if type(text) == "table" then
local ttext = text.text or 'Placeholder'
local caption = text.caption or 'Placeholder'
local ttype = textype or 'info'
local length = length or 5000
exports['TopXNotify']:Notify(ttype, length, ttext, true) -- caption or title not allowed on our notify yet
else
local ttype = textype or 'info'
local length = length or 5000
exports['TopXNotify']:Notify(ttype, length, text, true)
end
end