Use js const / var from Lambda function in a different position [closed]

I have this part of code in a Lambda AWS, it returns the correct value I send from external JSON.

exports.handler = async (event) => {

    /*
     * This lambda sends the payload received from an AWS event (Example: IOT button)
     * To a filemaker API using token authentification
     */

    //Log the received AWS event to the console
    const ostrons = ("Evento:" + JSON.stringify(event.id_record));
    console.log(ostrons);

Now I would like to use the const (ostrons) in a different part of the Lambda as a variable, how can do?
I tried with simple const = …. but nothing
Sorry I am learning js…