Welcome to the forum, but I fear that you will get minimal help here. This forum focuses on molded fiberglass towable trailers although some of us have had experience with other types and styles of RVs. Our propane
tanks are typically removable and located on the tongue.
The good news is that I may be able to help with your question or at least tell you where to look. You probably have a permanently mounted tank located under the floor. Based on my experience, it is probably on the curb side. Look for a hatch that does not have locks because quick access is sometimes needed for shutoff.
Hope this helps get you started. Enjoy your adventure.