How PostAsync on Firebase?

So i started use firebase, just to teste, and i tryed PostAsync, worked but for any reason it generate a random key:

As you can see generate that giant number as key, i dont want that, i want choose the key, but for any reason i cant.

    local Table = {
	["Value"] = 10,
	["Skills"] = {
		["PureBlaster"] = true
	}
}


local HttpService = game:GetService("HttpService")


--local URL = "https://universo-0-royale.firebaseio.com/Value.json?auth=jqVrVAtpYH29kAcOIqo7FZOGBcyAQ836XsRjMDkF"

local URL = "https://I WONT SHOW MY LINK OF COURSE/ValuesBro.json?auth=I WONT SHOW MY AUTH OF COURSE"
--local Value = HttpService:JSONDecode(HttpService:GetAsync(URL))
local Value = HttpService:PostAsync(URL,HttpService:JSONEncode(Table),Enum.HttpContentType.ApplicationUrlEncoded,false)

print(Value)

Obs: that key print on console too
91212d2e250366d08cf78af85b1601a3

Isnt the same number cause i dont have a recent picture, but that show the same.