too use litematica on sticky, i think you need fabric api, if you dont know how to add mods and what mods you need to run it, either a tutorial or asking someone would help you do it.
play.stickymc.com
StickyMC 1.17 & Season 2 Launch
You can download Litematica and make a litematic of it
There is the link for the Mod. It explains what you need and gives tips/ tutorials. Hope this helps
To summarize it all, find your '.minecraft' folder and the the 'mods' sub-folder offload the following mods into it
the one Rhia said, https://www.curseforge.com/minecraft/mc-mods/litematica/files
Malilib, this is the library mod it requires, https://www.curseforge.com/minecraft/mc-mods/malilib/files
Some mods require fabric API mod, https://www.curseforge.com/minecraft/mc-mods/fabric-api/files
after adding these too the mods folder, install this https://fabricmc.net/use/
after this, it should all be ready to launch in the mc launcher. hope this helps you