You just need to run both applications using:
mvn -f amqp-quickstart-producer quarkus:dev
And, in a separate terminal:
mvn -f amqp-quickstart-processor quarkus:dev
Quarkus starts a AMQP broker automatically, configures the application and shares the broker instance between different applications. See Dev Services for AMQP for more details.
Open http://localhost:8080/quotes.html in your browser and request some quotes by clicking the button.