...

Starting Load Test with the -ask flag will prompt you to specify the Java executable you want to run. This is helpful if you need to run with a different version or alternate distribution of Java. Connecting to a WebSphere application over SSL, for example, requires the IBM JRE. You can download the IBM JRE and use the -ask option when starting Load Test, which will prompt you to specify the alternate Java. See IBM WebSphere MQ 1 for additional information.  

Windows:

lt loadtest -ask

Linux and MacOS:

Load Test searches for a loadtest.config configuration file whenever it is started. If the file does not exist, Load Test and will create the file and print the location to the console. You will need to manually edit the configuration file if you want to change the Java runtime. For example:

adam-trujillos-macbook-pro:MacOS atrujillo$ ./loadtest
Found a new Parasoft Load Test installation. Parasoft Load Test will be configured.
Using /Library/Java/JavaVirtualMachines/jdk1.8.0_121.jdk/Contents/Home/jre/bin/java
Parasoft Load Test setup in /Users/atrujillo/Downloads/parasoft/soatest/9.10/Parasoft Load Test.app/Contents/MacOS/../../../Parasoft SOAtest.app/Contents/ParasoftSOAtest/eclipse/plugins/com.parasoft.xtestptest.libs.web_9.10.0.20161130/root completed successfully
Starting Parasoft Load Test...

The console may not print the location of the configuration file after the first start up, but it is created in the following directory so you can edit it any time:  <SOATEST_INSTALL>/eclipse/plugins/com.parasoft.xtestptest.libs.web_<version><VERSION>/root/

Load Testing SOAtest Functional Tests

...