Error in tutorial: travelRequestVar not defined

I'm following the tutorial at https://documentation.bonitasoft.com/bonita/7.6/getting-started-tutorial . I'm stuck at the "Run process with temporary forms" step. When I try to run the app, I get an error telling me that travelRequestVar is not defined.

It's complaining about the travelRequestVar.userId = BonitaUsers.getProcessInstanceInitiator(apiAccessor, processInstanceId).id line added to the initTravelRequest() script.

The first part of the stack trace is:

2017-12-09 07:50:17.044 -0500 SEVERE: org.bonitasoft.web.rest.server.api.resource.CommonResource USERNAME=walter.bates | org.bonitasoft.engine.core.process.instance.api.exceptions.SProcessInstanceCreationException: PROCESS_DEFINITION_ID=9021452999629912232 | PROCESS_NAME=Travel Request | PROCESS_VERSION=1.0 | org.bonitasoft.engine.expression.exception.SExpressionEvaluationException: Expression initTravelRequest() with content = <travelRequestVar.userId = BonitaUsers.getProcessInstanceInitiator(apiAccessor, processInstanceId).id
travelRequestVar.status = "pending"> depends on travelRequestVar is neither defined in the script nor in dependencies.
org.bonitasoft.engine.bpm.process.ProcessExecutionException: USERNAME=walter.bates | org.bonitasoft.engine.core.process.instance.api.exceptions.SProcessInstanceCreationException: PROCESS_DEFINITION_ID=9021452999629912232 | PROCESS_NAME=Travel Request | PROCESS_VERSION=1.0 | org.bonitasoft.engine.expression.exception.SExpressionEvaluationException: Expression initTravelRequest() with content = <travelRequestVar.userId = BonitaUsers.getProcessInstanceInitiator(apiAccessor, processInstanceId).id
travelRequestVar.status = "pending"> depends on travelRequestVar is neither defined in the script nor in dependencies.
at org.bonitasoft.engine.api.impl.ProcessStarter.start(ProcessStarter.java:113)
at org.bonitasoft.engine.api.impl.ProcessAPIImpl.startProcessWithInputs(ProcessAPIImpl.java:3044)
at org.bonitasoft.engine.api.impl.ProcessAPIImpl.startProcessWithInputs(ProcessAPIImpl.java:3038)

-- sorry about not formatting the block, but that makes it impossible to read :(

Can someone point out what I missed and what I need to do to fix?