Modrinth App puts its files in a certain place depending on your operating system. These are the default values; you can change this directory in the "App directory" section of the launcher settings.
⚠️ Modrinth App will break if you change the app directory to any directory that requires administrator privileges, such as Program Files on Windows. Do not change the directory unless you know what you are doing.
✔️ Modrinth App directory name has changed from com.modrinth.theseus to ModrinthApp in version 0.8.0 to improve compatibility with Minecraft. The app will automatically migrate your files after the upgrade.
Windows
On Windows, files are stored in %AppData%\ModrinthApp\ by default.
To navigate to this directory, press Win + R on your keyboard, then copy-paste %AppData%\ModrinthApp\ into the dialog box.
Mac
On Mac, files are stored in ~/Library/Application Support/ModrinthApp/ by default.
To navigate to this directory, open Finder and click on "Go" in the bar at the top of your screen. In that menu, click "Go to folder", then enter ~/Library/Application Support/ModrinthApp/ into the dialog box.
Linux
On Linux, files are stored in $XDG_CONFIG_HOME/ModrinthApp/ (usually ~/.config/ModrinthApp/) by default.
As a Linux user, you're expected to know how to navigate to this directory yourself.