on the startup screen there is a button labelled „Mods“. Click on it.
After that you can find a green button labelled „load mods“. Click that one and look for the right folder.
I recommend you drag the files to you desktop otherwise you might not find them. After that just make sure they are loaded properly and close the mods window. The game will then close itself, just restart it and you should be done. You can also find more help on the discord.
Also don’t download mods that are not from the official discord server.