Mongodb insert array of object using postman

I tried My Collection Structure like this is in node
app.collection(‘person’).insertOne({
name:req.body.name,
details:[{
age:req.body.details.age,
town:req.body.details.town
}]
});

In Postman I tried Like This
{
“name”:“abc”,
"details:[
{
age:“1”,
town:“efg”
},{
age:“2”,
town:“jkl”
}]
}

I get null values in my result.I need to know How to send this data to mongodb using nodejs with postman