Temporary solution until https://github.com/tauri-apps/tauri/issues/323 lands.
Depending on your use case, for example a Login with Google button, you may want to take a look at https://github.com/FabianLars/tauri-plugin-oauth instead. It uses a minimalistic localhost server for the OAuth process instead of custom uri schemes because some oauth providers, like the aforementioned Google, require this setup. Personally, I think it's easier to use too.
Check out the example/ directory for a minimal example. You must copy it into an actual tauri app first!
In case you're one of the very few people that didn't know this already: macOS hates developers! Not only is that why the macOS implementation took me so long, it also means you have to be a bit more careful if your app targets macOS:
Info.plist file at build time, the plugin can't change the schemes at runtime.tauri dev a little bit more pleasant, the plugin will work similar-ish to Linux and Windows in debug mode but you will see secondary instances show on the screen for a split second and the event will trigger twice in the primary instance (one of these events will be an empty string). You still have to install a .app bundle you got from tauri build --debug for this to work!