nodejs express rest api post displaying undefined - node.js

Question

im currently trying nodejs for the first time and im trying to make a rest api that i can link to my website that uses postgresql to get the data.
categories.js is the file im currently working on, it holds all get and post methods related to the categories table in postgres
Here's the current code in my categories.js:
var express = require('express');
const bodyParser = require("body-parser");
var router = express.Router();
const {Client} = require('pg');
router.use(bodyParser.json());
const client = new Client({
host: 'localhost',
user: 'postgres',
port: 5432,
password: 'admin123',
database: 'postgres'
})
client.connect();
/* GET categories listing. */
router.get('/', function(req, res, next) {
client.query(`select * from categories`, (err, result)=>{
if(!err){
res.send(result.rows);
}
else console.log(err.message);
});
client.end;
});
/* GET category listing by id. */
router.get('/:id', function(req, res, next) {
client.query(`select * from categories where id=${req.params.id}`, (err, result)=>{
if(!err){
res.send(result.rows);
}
else console.log(err.message);
});
client.end;
});
/* POST category listing by postman. */
router.post('/', (req, res)=> {
const category = req.body;
console.log(category)
let insertQuery = `INSERT INTO categories
(name, createdat)
VALUES ('${category.name}','${category.createdat}');`
client.query(insertQuery, (err, result)=>{
if(!err){
res.send('Insertion was successful')
}
else{ console.log(err.message) }
})
client.end;
})
module.exports = router;
the problem is, everytime i try to make a post method through postman using this script:
{
"name": "cat2",
"createdat": "13/05/201"
}
it posts an empty item into the database:
{"id":12,"name":"undefined","available":true,"createdat":"undefined"}
the get methods work normally by the way, but the post method doesn't
here's the categories table in postgres incase that helps
CREATE TABLE IF NOT EXISTS public.categories
(
id integer NOT NULL DEFAULT nextval('categories_id_seq'::regclass),
name text COLLATE pg_catalog."default" NOT NULL,
available boolean NOT NULL DEFAULT true,
createdat text COLLATE pg_catalog."default" NOT NULL,
CONSTRAINT categories_pkey PRIMARY KEY (id)
)

Answer 1

well well well, i found what the problem was lmao, and its actually embarassing.
well basically in the postman program, when i was inputing my data for it to be submitted to the database as json, i had the body selected in text form instead of json, which is why it couldnt recognize my data, cs it was in txt not json..
here's a pic incase someone does a stupid like i did
fix
mistake