Since this is going on a regular DVD and not a Blu-ray, you’re going to have to render the video again using the DVD Architect Pal video stream or DVD Architect Pal widescreen video stream template which will have to be customized as you can;t give it an HD file, only SD.
I always recommend using the bitrate calculator found at https://www.johncline.com/bitcalc110.zip and the customize it as follows.
Click the Settings button on the main screen, set the Safety Margin to 5% (default is 1%) giving you some extra room, set the audio to 192 Kb/s AC-3 (this is the default for Vegas) and set 1 kilobit = 1000 bits.
Exit this screen, set the video to the DVD-9 option, enter 2 hr. 33 min. and click VBR.
You should get 4064 / 6768 / 8464 (or close to it).
Render your project again using the appropriate template given above, click the Custom button, click the Video tab (if you’re not already one it), enter these numbers in the appropriate spot (you will need to add 000 to each set of numbers), select the 2-pass mode (takes longer but is worth it) click OK and start rendering.
Make sure to give it the same name as your audio file and render it to the same folder.
That way, when you load the video into DVDA, the audio will automatically follow.