You might want to check out this ongoing thread:
There is a difference between saying that Adam wasn’t real and the Genesis narrative is not history. People who say the Genesis narrative isn’t literal history take different positions on whether or not Adam existed as a “real person.” So people like John Walton think he existed in history, but the narrative about him is intended to be read as an archetypal theological narrative about humanity as a whole, not as a “historical” account of facts about his life. Others who see Adam as a figurative literary character see his presence in the genealogy as underlining Jesus’ humanity, not giving a genetic pedigree. Adam is the son of God in one of the NT genealogies, and we don’t take that as a literal genetic/biological/ancestral relationship.
I think one of the hard things for people coming from different perspectives to get is that in the ancient world true did not necessarily equal factual/history/non-fiction. Noah could have been a real person, and the flood narrative could have been based on some actual events, but the point of the story was to tell true things about God and humanity, not true facts about Noah and his experiences. It’s a different concept of why people tell “histories.” So in some ways, how much of the story is factual would not have had much bearing on how much of the story was considered “true” to the ancient audience. It’s hard to wrap our modern minds around that cultural difference and the fact that what went without being said for them is different than what goes without being said for us. I personally think God inspired the message, the communicative intent of the narrative and used it to communicate the truth he wanted to communicate. But it’s likely the communicative intent and the message was theological, not historical. I don’t think you prove the inspiration of Scripture by fact-checking it, because it is a huge modern assumption that the point of telling the story was to relay facts about history.