How do I report income from the sale of cryptocurrency when I don't have the requisite documentation?

I purchased a small amount of Bitcoin in 2011 and am aware of the exact amount acquired. At a later date, I transferred half of it into Ethereum. In 2024, I sold all my Ethereum holdings. Unfortunately, I can no longer access my Coinbase account, where these transactions were recorded. I had updated the account's authentication method to use a passkey tied to my smartphone, but after replacing the device, the new smartphone is not recognized as the passkey. Despite numerous attempts, the account remains unrecoverable due to a Catch-22 in the recovery process. As a result, I am unable to obtain the documentation required by TurboTax to accurately report the income from the sale of cryptocurrency. What steps can I take to properly report this on my federal tax return?"

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