How to add an interior wave port in HFSS?

Hi,
Could anyone show me how to add an interior wave port? As shown in the attached picture, I want to replace the lump port with a wave port. the impedance line can be the same direction.

I want to do that because the real source is a high frequency resonator made by asemiconductor device. it can generate more than one mode, I guess. I am confused by the HFSS's help. If anyone knows how to do it, could you please show me an example using my project attached?

thank you so much.

Place a thin box with of perfect conductor
with the face coincident with the rectangle to which you want
assign the waveport

then assign the waveport to the rectangle

Hope this helps
secondalinea