pull a sub document and just return it's value - mongodb

Question

i have this cart data in mydb, cart contains array of products :
{
"_id" : ObjectId("5f3a609dfb64f953c45bc97a"),
"user_id" : ObjectId("5f3a609dfb64f953c45bc979"),
"products" : [
{
"product_id" : ObjectId("5f3a609dfb64f953c45bc97f"),
"product_name" : "Cangkir",
"product_price" : NumberLong(10000),
"productavatar" : [
"default-product.jpg"
],
"merchant_id" : ObjectId("5f3a609dfb64f953c45bc97d"),
"merchant_name" : "Merchant Test 1",
"quantity" : NumberLong(1),
"buyer_note" : "Mohon dipacking dengan rapi",
"updated" : false,
"message" : ""
}
],
"created_at" : ISODate("2020-08-17T10:49:01.692Z"),
"updated_at" : Timestamp(1597661341, 19)
}
i want pull product in cart, and just return the product is pulled.
this is my query :
//first
db.getCollection('carts').findOneAndUpdate({"_id" : ObjectId("5f3a609dfb64f953c45bc97a"), "products.product_id" :ObjectId("5f3a609dfb64f953c45bc97f")},{"$pull" : {"products" : { "product_id" : ObjectId("5f3a609dfb64f953c45bc97f")}}},{"projection" : { "products.$" : 1}})
//second
db.getCollection('carts').findOneAndUpdate({"_id" : ObjectId("5f3a609dfb64f953c45bc97a")},{"$pull" : {"products" : { "product_id" : ObjectId("5f3a609dfb64f953c45bc97f")}}},{"projection" : {"products" : {"$elemMatch" : {"product_id" : ObjectId("5f3a609dfb64f953c45bc97f")}}}})
Result
{
"_id" : ObjectId("5f3a609dfb64f953c45bc97a"),
"products" : [
{
"product_id" : ObjectId("5f3a609dfb64f953c45bc97f"),
"product_name" : "Cangkir",
"product_price" : NumberLong(10000),
"productavatar" : [
"default-product.jpg"
],
"merchant_id" : ObjectId("5f3a609dfb64f953c45bc97d"),
"merchant_name" : "Merchant Test 1",
"quantity" : NumberLong(1),
"buyer_note" : "Mohon dipacking dengan rapi",
"updated" : false,
"message" : ""
}
]
}
this query is work to pull the product but the return value is not single pulled product.
This is what i expected return :
{
"product_id" : ObjectId("5f3a609dfb64f953c45bc97f"),
"product_name" : "Cangkir",
"product_price" : NumberLong(10000),
"productavatar" : [
"default-product.jpg"
],
"merchant_id" : ObjectId("5f3a609dfb64f953c45bc97d"),
"merchant_name" : "Merchant Test 1",
"quantity" : NumberLong(1),
"buyer_note" : "Mohon dipacking dengan rapi",
"updated" : false,
"message" : ""
}
is my approach cannot be works? or i must change another approach, i have read about aggregate but i bit more confused to me
Thanks