Changing the Birthdate on an ingame account

Recently I have started playing SWGOH again, and played awhile on a brand new account, then I remembered that I had an older account where I purchased the hyperdrive bundle, so I tried logging into it through the Apple ID, it didn't work because the old account's apple ID was my dads. So I went to his Ipad and logged into the account with this EA account, however on my phone when i try to link the account it says this:

I haven't added a birthdate to the EA account yet and I don't remember the one I put into the game itself (didn't use the real one for safety purposes), I spent 50 dollars on the old account and want to continue using it so if possible could you let me know how to change the age in swgoh, thank you. 

P.S. my player ID if needed HpM7v7ekSU-VT67zg7RsVQ