Why does the final check keep asking for the QBI Passive Op Loss must be entered?

If you had losses from prior years, those losses would be carried to future years to offset your QBI. If you did not have any, enter 0.

On what Form /Line do I find this information?

Go to the search menu, type in --  qbi -- then press the magnifying glass (not enter), then select the jump to link.

@lilly54