Request RPGM How to make a library mod for a game that doesn't have this?

[ldacombat123]

Let me get straight to the point, here's a typical game with no "gallery" or "recollection room" : https://f95zone.to/threads/mh-skybride-final-zzzz.150688/
Can someone help me create a simple library mod or direct me to a suitable tool to do it? Sorry if my writing is a bit confusing because of using google translate