Correct answer is ${training.host}
-------------------------------------------------------------------------------------------------------------------------------------------------- How to Configure Properties to Mule 4.X Platform?
1) Go to /src/main/resources project directory.
2) Create a configuration file with the name configuration.yaml inside the newly created config folder.

3) Go To Project > Global Element > Create > General >select the configuration.yaml file create in step- 2)

4) To verify develop a simple flow with HTTP listener which has above entries. Put the logger that prints the values on console.

5) Additional info: Similarly, when you want to access this port in DataWeave you need to use p function