Still stuck.
Here are a few other threads on the subject:
[how to render frame by frame manually)
[Panda3d server without gui)
[[SOLVED] run panda without DirectStart)
[Panda Without Render Window)
panda3d.org/manual/index.php/SPE
ru.is/kennarar/hannes/useful … ine.1.html
[makeGsg, creating offscreen buffers without a window)
[Why these codes couldn't create a hiden window)