Not an expert here, but I assume the wallet used a different algorithm to generate your 12-word phrase and keyed those 12 words specifically to your private (and maybe public) keys. So, the tool you used will not be able to give you the correct private key.

Much better idea would be to get the private keys directly from coin.space. If they don't have a way for you to get those keys, then use a different wallet, like Exodus or Electrum.