Postman Pre-Request Script

prereq.script.js

// For usage in Postman as Pre-Request Script to get token.   
// Requires a environment file with 'client', 'secret', 'url' and 'authorization' key/value pairs.   (leave the authorization key blank)

pm.sendRequest({
    url: pm.environment.get("url") + '/auth/token',
    method: 'POST',
    header: {
    "content-type": "application/x-www-form-urlencoded"
    },
      body: {
          mode: 'urlencoded',
          urlencoded: [
            {key: "grant_type", value: "client_credentials", disabled: false},
            {key: "client_id", value: pm.environment.get("client"), disabled: false},
            {key: "client_secret", value: pm.environment.get("secret"), disabled: false}
        ]
      }
}, function (err, res) {
    console.log(err ? err : res.json());
    pm.environment.set("authorization", "Bearer " + res.json().access_token);
});