Morphy Richards Astral RV fridge

Question

I have acquired a small rv trailer with a fridge that we know absolutely nothing about.  I have never heard of this brand of rv fridge before.  It does not work on electricity as far as I can tell.  It has two large D size batteries in it and I am not sure what they are for.  It is connected to propane and I believe that it will run off the main battery as well.  We would like to know how to go about lighting it.  We know that it has to be as level as possible before we light it and we have done that part.  As I said, we do not know anything about lighting a RV propane fridge.  Can you tell us how to do it?  Also we would like to find a manual for it.  Can you help us with this as well?  Thank you so much.

Roxann