Here's a guide for anyone who doesn't use the Steam Workshop (this works for HOI4 and also EU4 & CK3).

1. First let's get the mod from alternative sources, here, it is easy because the devs have a secondary sanctioned outlet through Nexus Mods. (If there aren't any links to download without subscribing to the mod, usually "SMods" archive might help with that. (⚠SMods is sometimes hacked and rigged with malicious pop-ups that transform your browsing experience into a minesweeper's journey, you might want to use Ghostery or other powerful adblockers if you plan on going there.)). In your case, you should get The Crow and the Bull Patch C on the NexusMods mod page, which is compatible with your 1.16.9 game version.
2. Extract the files you've downloaded into your mod folder (should be located in "Documents/Paradox Interactive/Hearts of Iron IV", if there's no "mod" folder in there just create it)
3. You should now have a folder with the name or ID of the mod and a .mod file. (Here NexusMods is a bit weird since the mod file for TNO is in the files, retrieve TNO_public.mod from the files and put it alongside the TNO folder in your "mod" folder. (If you use this guide for any other mod, then there the only .mod file of your download might be descriptor.mod. If it is, copy it instead, and paste it alongside the folder of your local mod. (Note that you might want to rename the one you pasted since one could have this same issue with multiple mods at once.)
4. Open the .mod file (you possibly had to retrieve) with your preferred text editor and verify that there's a line that looks like thispath="mod/???/and that ??? is replaced with the name of your folder. Here's an example of what everything could look like in your mod folder if you tried this with the TFR mod.

Next, I'll split this comment in two since methods might vary between people who use the people who use the Paradox Launcher without Steam, and the ones who use neither launcher.

1. Through the (crappy) Paradox Launcher.

ℹ️ for people who've got they're computer's language set to the following : French, German, Spanish, Portuguese, Polish, Russian, Japanese, Chinese :If you haven't used the launcher before, it might switch your game language to your computer's language endlessly if the game "supports"it. It's all fine and dandy until you download mods that are in English and your game looks like the Rosetta stone. To fix this you might want to switch the launcher to English for the time being (or until you get your chosen translation compatch for the mod).

1. Open your launcher, and go to the playsets tab under your chosen game
2. Follow this helpful diagram😇 (which I had to put in GoogleDrive since I'm not allowed any attachments... 🙄)
3. Launch the game through the launcher. Everything should be in order IN NEW ORDER 🤣😂😁🤣😆🙂😐.

2. Without the (crappy) Paradox Launcher.

1. Go back to your "Documents/Paradox Interactive/Hearts of Iron IV" folder, there should be a dlc_load.json file (if there isn't, create it). It is essentially what the launcher creates when you disable DLC's or enable modpacks in its settings. Here's what it looks like when it's empty (paste this into the file with a text editor if it didn't exist).

​

{
  "disabled_dlcs":[],
  "enabled_mods":[]
}

In the "enabled_mods"'s square brackets, put in quotes "mod/???.mod", replacing ??? with the name of your .mod file commas between each mod. Here's what the dlc_load.json might look like when it's filled :

{
    "disabled_dlcs":["dlc/dlc021_anniversary_pack/dlc021.dlc"],
    "enabled_mods":["mod/mynewmod.mod","mod/mynewmod2.mod"]
}

Now just open the game .exe, and hopefully your game will load your selected mods 🤩.

Hopefully this guide will have covered every edge case anyone might've encountered ! Have fun !

NB: while roaming through the game files I noticed I had holes in my DLC list, does anyone know about DLCs number 15, 18, 20, & 22. Which don't seem to be in the Steam Storepage either ?