I am declaring a String Parameter in Jenkins - 

```
Name is SLACKTOKEN 
Value is qwsaw2345

```

My Jenkins file has script

```
pipeline {

    agent { label 'trial' }

    stages {
        stage("Build Docker Image") {
            steps{
                sh 'docker build -t trial:latest --build-arg SLACK_SIGNING_SECRET=${SLACKTOKEN}'
            }
        }

    }
}

```

I tried like this, but it didnt work. Could you please let me know how can I pass a value from Jenkins string parameter to Jenkins declarative script file.
I have added the Password parameter in job like below 

[![enter image description here](https://i.stack.imgur.com/keQ3h.png)](https://i.stack.imgur.com/keQ3h.png)