You can have a design without bent up bars by checking the Design without bent up bars option in the Beam Settings dialog, Steels tab.

For existing beams:

Select the beams, click Properties (Ctrl + E) and select the Design without bent up bars option in the Steels tab.

For newly defined beams:

Click the beam command and open the Beam Settings with the Settings icon in the beam toolbar. Click the Design without bent up bars option in the Steels tab.