How can I get the "value" of a DynamicReferenceParameter in Jenkinsfile

I have a DynamicReferenceParameter with choiceType:'ET_FORMATTED_HTML'. I can see it changes it's "display value" according to the script code. However when I try to read it's "value" from the Jenkinsfile, I only see empty string. Is there a way to get the same html value there?

The other parameters I can see with: "$params.FOO", but not for this DynamicReferenceParameter

For me i have to set the html input value field to

value

And set omitValueField: true,

as below

 [$class: 'DynamicReferenceParameter',
        name: 'DEPLOY_VERSION',
        description: 'Version for deployment',
        choiceType: 'ET_FORMATTED_HTML',
        omitValueField: true,
        referencedParameters: 'ENV,BUILD_VERSION',
        script: [
            $class: 'GroovyScript',
            fallbackScript: [
                classpath: [],
                sandbox: true,
                script: "return ['Could not determine version']"
            ],
            script: [
                classpath: [],
                sandbox: true,
                script: """
                if (ENV == 'prod') {
                    return '<input name="value" value="" placeholder="Enter deployment version" style="width:300px; height:30px; font-size:14px;" />'
                } else {
                    return '<input name="value" value="' + BUILD_VERSION + '" readonly style="width:300px; height:30px; font-size:14px; background-color:#d3d3d3;" />'
                }
                """
            ]
        ]
    ]

Then get the value like this

  echo "deploy version : ${params.DEPLOY_VERSION}"