Go to your email, open the email sent to you by GC, and then follow the instructions to validate your account. Most games have such a feature to prevent you from making multiple accounts, or from allowing bots to flood your game with fake accounts. It`s not crab.
If you haven`t gotten one in your email yet, you can do it manually.
To send it manually please go to option --> Account info, From there, check the email address you entered during sign up is valid, and then press "Send validation email"
Then please wait a few mins for the email to arrive in your inbox
Sometimes the email is misidentified as spam and may be places in your junk mail folder, please ensure you have checked this
Using aol addresses has known issues, if you have signed up with an aol email address, please use another address (Many free email providers can be found using a search)
If the above does not work, click on
Help Center > Ask > Questions > Validation