How to enhance Data Source "P&L - Plan/Actual" with "Alternative G/L Account" field

Dear community,

we would like to make "Alternative G/L Account" field available for "P&L - Plan/Actual" (C_PROFITANDLOSSPLANACTQ2903) reports.

We've tried to enhance the following data sources:

But we have only been able to extend it for the "P&L - Actuals".

For the "P&L - Plan/Actuals" we cannot see the field available.

Any clue on how to answer this "nice to have" from our client?

Thank you in advance.

Best regards,

João