How to Fix A Hole
Fortunately, it’s independent of the header to the right.
Some remodelers might roll the dice and leave it, but this header sits on two load bearing walls. Additionally, the project involves a new, heavier roof that will make those walls even more critical.
The most obvious solution is to replace the entire header. Another approach would be to bolt a ½-inch reinforcing steel plate across the face of the header but that will only work if the interior finish allows for the extra protrusion. A third option is to place laminated beams on the back side.