There are two ways of adding mods into Citra

From Citra
- Extract any mod from compressed .zip or any other format to folders.
- Open up Citra inside RetroDECK Configurator by pressing Open Emulator - Citra.
- Right click on the game you want to add mods into.
- Click on Open Mods Location.
- Paste the mod files inside that directory, each folder is stored by the TITLLEID of the game.
- Quit Citra

From the mod folder directly
- Extract any mod files from compressed .zip or any other format into folders.
- Go into ~/retrodeck/mods/citra/. The folders are all named by TITLEID.
- Past the mods into the right ~/retrodeck/mods/yuzu/<TITLEID> folder.

Related wiki article can be found here:
https://github.com/XargonWan/RetroDECK/wiki/Citra%3A-Mods#citra---3ds

The RetroDECK Team