如何在管道中使用jenkins版本号插件

我正在使用版本号詹金斯插件在詹金斯版本。2.107.2条。下面的管道代码不工作。有什么帮助来解决这个问题吗?

管道代码

pipeline {

            agent any
            stages {
                stage('Pre-Build') {
                    steps {
                        sh 'echo Building Docker' 
def tag = VersionNumber (versionNumberString: '${BUILD_DATE_FORMATTED, "yyyyMMdd"}-develop-${BUILDS_TODAY}')
}

                        } 

                }

}

错误:

Running in Durability level: MAX_SURVIVABILITY
org.codehaus.groovy.control.MultipleCompilationErrorsException: startup failed:
WorkflowScript: 8: Expected a step @ line 8, column 1.
   def  tag = VersionNumber (versionNumberString: '${BUILD_DATE_FORMATTED, "yyyyMMdd"}-develop-${BUILDS_TODAY}')
   ^

1 error

    at org.codehaus.groovy.control.ErrorCollector.failIfErrors(ErrorCollector.java:310)
    at org.codehaus.groovy.control.CompilationUnit.applyToPrimaryClassNodes(CompilationUnit.java:1085)
    at org.codehaus.groovy.control.CompilationUnit.doPhaseOperation(CompilationUnit.java:603)
    at org.codehaus.groovy.control.CompilationUnit.processPhaseOperations(CompilationUnit.java:581)
    at org.codehaus.groovy.control.CompilationUnit.compile(CompilationUnit.java:558)
    at groovy.lang.GroovyClassLoader.doParseClass(GroovyClassLoader.java:298)
    at groovy.lang.GroovyClassLoader.parseClass(GroovyClassLoader.java:268)
    at groovy.lang.GroovyShell.parseClass(GroovyShell.java:688)
    at groovy.lang.GroovyShell.parse(GroovyShell.java:700)
    at org.jenkinsci.plugins.workflow.cps.CpsGroovyShell.doParse(CpsGroovyShell.java:131)
    at org.jenkinsci.plugins.workflow.cps.CpsGroovyShell.reparse(CpsGroovyShell.java:125)
    at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.parseScript(CpsFlowExecution.java:560)
    at org.jenkinsci.plugins.workflow.cps.CpsFlowExecution.start(CpsFlowExecution.java:521)
    at org.jenkinsci.plugins.workflow.job.WorkflowRun.run(WorkflowRun.java:325)
    at hudson.model.ResourceController.execute(ResourceController.java:97)
    at hudson.model.Executor.run(Executor.java:429)
Finished: FAILURE

这个链接 How to use jenkins version number plugin in Jenkinsfile? 有答案但不适合我。