How do I assign a prefab's Instance ID, that was converted to string, as a GameObject variable in a c# script?

Sorry if this was already answered/noob question, but, unfortuantely, I can’t seem to find much information on how to use the instance ID effectively.
I have a gameObject set as a prefab during runtime that I am attempting to save as part of a .json by converting the unique instance ID of the instantiated object into a string. I think I am doing this correctly as far as saving the information goes, but the problem arises when trying to assign that saved reference point as a game object upon loading into the scene.

My question is: Is there a way I can use this saved string of the object’s instance id to assign it as a declared ‘Game Object’ variable in script, and if so, how would I go about it? Was looking through, but couldn’t find a way to set it.

Here’s a snipit of my code:

public void Load_Player()
{
    Saveable_Object_Player savedata = Save_Manager.Load_Player_Stats();

    for (int i = 0; i < PlayerDeck.Length; i++)
    {
        PlayerDeck <em>= savedata.Prefab_Cards_in_Deck_Instance_IDs*;*</em>

}
}
I’m pretty sure using ‘GameObject.name =’ won’t work, but I’m not sure what else would be used here as I can’t assign a GameObject variable to equal to a string, and I’m not sure how to implicitly convert it properly. Is there a component I can use for the GameObject variable here to set the reference the prefab id (that was converted to string)?

Figured out what was going on here. Unity has some issues when it comes to reinitializing prefabricated objects straight from the folder during runtime. UnityEditor tricks won’t work during runtime.

There are two seperate ways to work around this. Including the prefabs in the Resource folder, which is repackaged later in your builds or by including references to the prefabs in your scene in like a game manager or some sort. Luckily, I have an easy way to differenciate all the prefabs in my array. Card Set Numbers!!! Never thought I would be so happy that that variable exists. Thank you TCG Designers for making my life easy. XD. Anyways, I found my workaround and why I was having such an issue with it before.

public void SavePlayerData(){
for (int i = 0; i < player.PlayerDeck.Length; i++) //specific prefabs of player deck
{
if (player.PlayerDeck == null)
{
break;
}
Prefab_Cards_in_Deck_Instance_IDs = player.PlayerDeck*.GetComponent<Base_Card_Attributes>().SetNumber;
_}
}*_