You have 3 options:

Option 1 - I believe that you have my Collection 02, correct? => go to Structure => Pitched Beams (outlined in green in the image below) => you will find beams with different settings and pitches (2:12, 4:12, 6:12, etc) => if you hover the mouse over the thumbnails (preview bar), you will see the details (pointed with a blue arrow in the image below) => select and place the beam => resize and elevate as necessary.

Option 2 - If you wish to adjust the angle of a horizontal beam from the Punch Furnishing library (Building Elements) => place and select the beam => right click => 3D Custom Workshop => the Power Tool will open => Visualize in 2D => adjust the angle or rotate as desired.

Option 3 - Your program includes the Ceiling Designer Power Tool => Launch this Power Tool => Ceiling Beams => Draw the beam => adjust dimensions, elevation and pitch.

Hope this helps.