To find your Private Key of your 12-word seed wallet, first tap on the most right icon on your navigation tab bar to go to Settings. There, tap on Backup Wallet. After confirming your PIN you will be taken to a screen with your 12-word seed and your Private Key for you to back up somewhere safe (we usually write it down on a piece of paper). You can also use the Copy to Clipboard button.
Be aware to use this safely and secure. We don't save your Private Key or 12-word seed into our database. Private Key data is only shown to you.