Your parents will need to set up Parental Controls on your account to enable the Text Chat feature. This requires that they enter a valid email address, a password, and purchase a subscription that confirms they are over the age of 18 through their credit card information.
To Enable Parental Controls on your master account you will first need to login with your game account login and go to My Accounts.
Once in My Accounts you will need to click on the Enable button next to Parental Controls under Account Management. You will be prompted to enter an email and a password. Once this is complete hit save.
You should then get confirmation that they are turned on.
Once Parental Controls are enabled, your parents can set your chat and gifting permissions.