Retirement tax questions

This is maddening! Taxpayer wants to know how to handle distribution of corpus on the 1041 and gets answers on how to handle distribution of income!

Yes, we understand that the beneficiary doesn't have to report such distributions. But does the trustee have to report it on form 1041 and where on that form or its schedules do we report it, exactly? I see references to Schedule B, but when I try to open Schedule B the only thing that comes up is Schedule B QBI aggregation statement which is unrelated.