To be further detailed in what I'm looking to achieve. My animation, which I've already enabled onion skinning to be on with the desired settings, when exported only exports the drawn keyframes. What I would like to do, if possible, is to render out my animation to include the onion skinning which are very usefull visually in creating light inbetweens, giving me the desired look.
Onion skinning, in 2D computer graphics, is a technique used in creating animated cartoons and editing movies to see several frames at once. This way, the animator or editor can make decisions on how to create or change an image based on the previous image in the sequence. Onion Skin is neither a visual effect nor a filter.