You have proven yourself to be a Bitcoin user!
There are two ways to qualify for this achievement:
1. Use your Bitcoin wallet to sign a message with the content "Achieve Mint Bitcoin User Proof" (without quotes). When applying for this achievement, send the Bitcoin address used to sign the message and the signature in the Achieve Mint message sent along with the achievement award request. Once the signature has been verified you will be awarded this achievement.
2. If your Bitcoin wallet does not support message signing, after requesting to be awarded this achievement, you will be sent a message with a Bitcoin address. Send any amount of BTC to this address. Once the BTC has been received, you will be awarded this achievement.