How to execute SoapUI test cases for different environments

Environment is a feature of Pro edition.
However, in the Open Source edition, you could do the following:

a. Use project property, say APP_URL and and use property expansion in the service / interface level i.e., ${#Project#APP_URL} and assign it for all the test cases and test requests. Save the project after changes

b. use SOAPUI_HOME/bin/testrunner (.bat/.sh) command line utility to execute the project. Note that here user do not have to modify the project property each time when url changes. Instead pass the -P APP_URL=<new ip address> to testrunner.

c. Even if you use UI to execute, just change the value of APP_URL property value as needed.

Hope this helps.