It has a good effect
Automatic payments in itself has nothing to do with credit scores or credit history. As long as the statements are paid before the due date, you are building good credit history and increasing your score.
It doesn’t matter is you’re using automatic payments or not, as long as payments are made on time.
The only point is not to make the payment to early. You need to wait for the statement and only then make the payments. If you don’t – your balance will show zero, and that has the same effect on credit scores as having no card at all.
So just make sure that your automatic payments are set to any date between when the statement arrives and the due date.