You could try
date { match => [ "[order][createdOn]", "YYYY-MM-dd HH:mm:ss" ] target => "[order][createdOn]" }
date { match => [ "[order][updatedOn]", "YYYY-MM-dd HH:mm:ss" ] target => "[order][updatedOn]" }
which (for me, in GMT-0400) results in
"order" => {
"totalPrice" => 120,
"createdOn" => 2024-05-27T17:23:29.000Z,
....
"updatedOn" => 2024-05-27T17:23:29.000Z
},
Set the timezone option on the date filters if you need to.