The guide provided by Abdussamad in that thread won't help OP.
OP should recover a 2 of 3 multi-signature wallet. That thread is about recovering a 2 of 2 multi-signature wallet and is not related to OP's issue.
The weird thing is there is no announcement from Coinbase that they are going to terminate Vault Wallet and honestly creating a Vault Wallet does not generate a private key it requires only 2FA and another email as co-signer.
See this:
https://www.talkimg.com/images/2023/10/29/TiRVa.jpeghttps://help.coinbase.com/en/coinbase/managing-my-account/other/the-multisig-vaultCoinbase multisig vault is 2 of 3 multi-signature wallet.
One of the keys is owned only by the user. One of them is stored by coinbase and the user has no access to that. One of the keys (which is encrypted) is owned by both coinbase and user.
If you own two of the keys, you must be able to spend your fund without relying on Coinbase and without any need to 2FA or email verification.
