Based on our discussion your request type is not raw, it is āx-www-form-urlencodedā.
so try this snippet,
console.log(pm.request.body.urlencoded);
Similar to this topic.
You can refer this link for more details.
@harutharut Itās all the same details we discussed yesterday, sharing it here so that it might be useful for someone in future 
Please let me know if thereās still any issue.