If you have signed up to Hive with 3Speak, by default, you can only use 3Speak. If you would like to use other dApps such as PeakD, Hive.blog, Splinterlands etc. you will need to request your private keys from 3Speak. This will automatically generate and send you private keys that can be used for managing your Hive account.
To request your keys, please visit: https://auth.3speak.tv/3/requestKeys