Firebase REST API - POST Request - rest

Question

I'm trying to add records to my Firebase database as follows:
So basically we have matches -> user_supplied_id -> {id,location}
This is achievable using the following code and the Swift API:
let matches = Database.database().reference().child("users").child(UserDefaults.standard.object(forKey: "uid") as! String).child("matches").child((all_listings?[index].listingId)!)
let newBookData = [
"id": all_listings?[index].listingId,
"location" : all_listings?[index].location
] as [String : Any]
matches.setValue(newBookData)
I am now trying to replicate this behaviour using the Firebase REST API. I'm basically sending a POST request to the address:
https://PROJECTID.firebaseio.com/.../matches/-LOpJmU9yj4hAocHjnrB.json
with the following data:
"{\"id\":\"-LOpJmU9yj4hAocHjnrB\",\"location\":\"Edinburgh\"}"
However, this results in the following outcome instead:
As you can see, it creates an additional ID and level of nesting before adding the elements to the database. How can I fix this?

Answer 1

Don't use POST. According to the documentation:
To accomplish the equivalent of the JavaScript push() method (see Lists of Data), you can issue a POST request.
You don't want a push here. A push operation creates a new random push ID and makes that the key of the data you provided.
If already you know the location you want to set (it looks like you already have a known push id), just use a PUT to set the data at that location.