To run the sample follow these steps:

com.auth0.samples://__AUTH0_NAMESPACE__/capacitor/com.auth0.samples/callback

com.auth0.samples://__AUTH0_NAMESPACE__/capacitor/com.auth0.samples/callback

capacitor://localhost, http://localhost

Check that mobile development environments for Android and iOS are setup correctly. For iOS, CocoaPods must be installed.
Make sure Node.JS LTS is installed and execute the following commands in the sample directory:

npm install
npm run build

# to test it in iOS
npx cap run ios

# to test it in Android
npx cap run android

Read more about the Capacitor development workflow on Capacitor's docs site.

What technology are you using for your web app?