But that's not in Scripture, yet you take that as fact.
The closest thing that I know of in Scripture concerns God's knowledge and plan for those whom He would later create, not that they previously existed until creation but in His own mind:
"Now the word of the Lord came to me saying, 'Before I formed you in the womb I knew you, and before you were born I consecrated you; I haw appointed you a prophet to the nations." (Jeremiah 1:5)
"For whom He foreknew He also predestined to become conformed to the image of His Son, that He might be the first-horn among many brethren." (Romans 8:29).
It’s in our additional scripture — modern day revelation — which I know you don’t believe, so I don’t expect you to accept it. I’m just telling you what we believe. I’m not debating.