The gusset image appears in red. Use Shift-Up or Shift-Down to adjust the size of the gusset and use the arrow keys to move it to the desired position. Pressing 5 switches between large and small movements and pressing zero switches to very small movements.
Once the gusset image is correctly sized and located, press Ctrl-Enter. Enter the gusset description, weight and weld size as shown below.
When you hit Accept, the welds appear as shown below.
Press F4 to update the Bill of Materials.