Hello @kartik,
1.You can create a new route to show the csrf token using your controller with help of the function below. (Use a Get request on the route)
public function showToken {
echo csrf_token();
}
2.Select the Body tab on postman and then choose x-www-form-urlencoded.
3.Copy the token and paste in postman as the value of the key named _token.
4.Execute your post request on your URL/Endpoint
Hope it helps!!