First as a quick note, this is based on the release system found here: https://github.com/MADH95/JSONLoader/releases

INSTALLATION

Setting up the API

Installing with a Mod Manager

Download and install Thunderstore Mod Manager, Gale or r2modman.
Click the Install with Mod Manager button on the top of BepInEx's page.
Run the game via the mod manager.

If you have issues with Mod Managers head to one of these discords;

Thunderstore Support Discord: Here
R2ModMan Support Discord: Here
Gale Mod Manager Support Discord: Here

Installing Manually

Install BepInEx by pressing Manual Download and extract the contents into a folder. Do not extract into the game folder!
Move the contents of the BepInExPack_Inscryption folder into the game folder (where the game executable is; usually found here: C:\Program Files (x86)\Steam\steamapps\common\Inscryption).
Run the game. If everything was done correctly, you will see the BepInEx console appear on your desktop. Close the game after it finishes loading.
Install MonoModLoader and extract the contents into a folder.
Move the contents of the patchers folder into BepInEx/patchers (If any of the mentioned BepInEx folders don't exist, just create them).
Install Inscryption API and extract the contents into a folder.
Move the contents of the plugins folder into BepInEx/plugins and the contents of the monomod folder into the BepInEx/monomod folder.
Run the game again. If everything runs correctly, a message will appear in the console telling you that the API was loaded.

For any additional mods create a new subfolder, it can be called anything and extract the zips archive into it and if there is a BepInEx folder within the zip instead drop the contents of that folder into the BepInEx root for the modding instance. EX;

BepInEx // These go within the BepInEx root folder
|-- config
|-- patchers
|-- plugins
|-- monomod
|-- core
plugins // Files within go into the created plugin subfolder that was created for the mod
|-- Art
|-- Scripts
|-- MyMod.dll
manifest.json     --|
README.md           |-- These can be ignored but if you want to keep them put them in the plugin subfolder
CHANGELOG.md        |--
icon.png          --|

Run the game once more and everything should be correct and working.

Installing Manually (XBOX Game-Pass)

Install BepInEx by pressing BepInEx_x64_5.4.21.0.zip and extract the contents into a folder.
Move the contents into the game folder (where the game executable is; usually found here: C:\XboxGames\D30AC640-4EC1-4D15-96F3-384052F09699\Content).
Run the game. If everything was done correctly, you will see the BepInEx console appear on your desktop. Close the game after it finishes loading. (psst. Enable Logging in BepInEx/config)
Install MonoModLoader and extract the contents into a folder.
Move the contents of the patchers folder into BepInEx/patchers (If any of the mentioned BepInEx folders don't exist, just create them).
Install Inscryption API and extract the contents into a folder.
Move the contents of the plugins folder into BepInEx/plugins and the contents of the monomod folder into the BepInEx/monomod folder.
Run the game again. If everything runs correctly, a message will appear in the console telling you that the API was loaded.

BepInEx // These go within the BepInEx root folder
|-- config
|-- patchers
|-- plugins
|-- monomod
|-- core
plugins // Files within go into the created plugin subfolder that was created for the mod
|-- Art
|-- Scripts
|-- MyMod.dll
manifest.json     --|
README.md           |-- These can be ignored but if you want to keep them put them in the plugin subfolder
CHANGELOG.md        |--
icon.png          --|

Run the game once more and everything should be correct and working.

Installing on the Steam Deck

Download r2modman on the Steam Deck's Desktop Mode and open it from its download using its AppImage file.
Download the mods you plan on using and their dependencies.
Go to the setting of the profile you are using for the mods and click Browse Profile Folder.
Copy the BepInEx folder, then go to Steam and open Inscryption's Properties menu
Go to Installed Files click Browse to open the folder containing Inscryption's local files; paste the BepInEx folder there.
Enter Gaming Mode and check 'Force the use of a specific Steam Play compatibility tool' in the Properties menu under Compatibility.
Go to the launch parameters and enter WINEDLLOVERRIDES="winhttp.dll=n,b" %command%.
Open Inscryption. If everything was done correctly, you should see a console appear on your screen.

Mac & Linux

Follow the steps here first: https://docs.bepinex.dev/articles/user_guide/installation/index.html
Next do steps 4-10 of the Manual Installation
Your game should be setup for inscryption modding now

If you have any issues with Mac/Linux, Steam Deck, or Manual head over to the discord for this game:

Inscryption Modding Discord: Here

Installing the Package

Manager

Open the Application, Navigate to the Game, Navigate to the Profile.
Press Browse or the Manager's equivalent
Install MADH95Mods - JSONCardLoader.
When you launch JSONLoader is now installed.

Manual

Press Download
Extract the Zip to a new folder.
Take the files and folders under plugins of the zip and move them up a folder.
Delete the plugins folder from the Extracted directory.
Now navigate to the location of your BepInEx install from your earlier setup for the API.
Navigate to plugins and add a folder entitled MadH95-JSONCardLoader, if theres a previous version of JSONLoader installed it should be fine, but I'd advise removing it to keep storage down.
Move the setup from steps 2-4 into the folder you created in step 7.
Now if all went well you should see the game warn [Warning: BepInEx] Plugin [JSONLoader 2.7.0] targets a wrong version of BepInEx (5.4.20.0) and might not work until you update, this has no relevance to anything and you can safely ignore it, but if the version is 2.7.0 than you have the correct version of JSONLoader installed.

Get the Thunderstore App

Installation (Based on Thunderstore Release System)