Game says I don't have early access key but I purchased through Steam

Unfortunately, we aren't able to assist with this issue over the forums. Please contact us at support@grindinggear.com so we can look into this with you. Be sure to include your Path of Exile account name (including four-digit discriminator) as well as the names of a few of your characters so that we are best able to look into things with you.

If you obtained your early access through purchasing one of the Early Access packs, please also include the transaction ID of the purchase. This can usually be found alongside your receipt of payment provided to you by the payment processor you used.

If you obtained your early access by redeeming a key, then the key's status may have been revoked if the original purchase was refunded or charged back. If this is the case, you may want to reach out to whoever you received the key from to check with them regarding the validity of your key.