You'll need to sign a message from a staked address as explained in this thread:
If in case you do not know how to sign a message. Read this topic created by shorena.
How to sign a message?!After posting your signed message here:
Stake your Bitcoin address here made by tomatocage. Move your topic in Meta thread or PM theymos or cyrus regarding your account issue.
Bump your thread every 24 hours to avoid spamming.