[Networking] Ped created on server, client can't access entity from netId

To fully understand why we need to use statebags, you need to first understand the entities/player culling for the client, When an entity or a player is too far from the client. it does not exist for that client.
With Statebags however, Because when the client is within the radius of that player/entity, That player/entity gets recreated for him, because its getting created for the client. if there is any statebags set to it, that statebags also gets created for that entity/player, This triggers a Statebag change event that can be listened to with AddStateBagChangeHandler, So the whole reason for using a statebag is to see when that specific entity has been created.
After looking at your code, it seems all the client has to do is setting the actual ox target,
There are alot more ways you can achieve this in ox_target that does not involve having a statebag handler constantly adding a new ox_target zone for that specific ped.
You can add the ped Models in a global exports.ox_target:addModel , Store the netids that you have created with addPlacedPed in a table. add a canInteract logic that checks if that entity is networked and if it is ,check if the netid for that entity exists in the table that you have stored.
Below is just a simple adaptation of what i explained, however you need to store the placed peds netids inside a table, for now i use a dummy placedPeds table. you can name it anything. but make sure the netids are stored as keys within the table

exports.ox_target:addModel({ 'pedmodelnumber1', 'pedmodelnumber2' }, {
    {
        name = 'talk',
        icon = 'fas fa-comment',
        label = 'Talk',
        distance = 2.0,
        canInteract = function(entity, distance, coords, name, bone)
            if not NetworkGetEntityIsNetworked(entity) or not placedPeds[NetworkGetNetworkIdFromEntity(entity)] then -- Checking if the entity is networked, and checking if it exists in our table of placedPeds 
                return false
            end
            return true
        end,
        onSelect = function()
            TriggerEvent('startConversation', config.conversation)
        end
    }
})

Also As Colbss Said , if the peds are truly static and they are just interactive npcs for opening UIs and etc… , You can Create them on for every client themselves(setting the isNetwork argument to false ofcourse!) and use addLocalEntity instead of going through these fuss,
To make this even better you can set a distance check wiht using ox_lib zone system for creating/removing the peds when the player gets near them or goes too far, this is a good practice to avoid having too many unused peds on the client.