Change in Roth Contribution After Filing

I am helping my son with his 2022 tax returns.  After he filed his returns recently, we determined that he can contribute more to his Roth (up to the $6,000 maximum) than he originated entered into Turbotax. Even though nothing about the Roth was included on his federal return, he is using Turbotax to keep track of his contributions through the years.  How do we change the 2022 Roth contribution amount in Turbotax now that he has already filed?