JSONDecode unkown error, Trello API Help?

I'm trying to make a database where the game's Creator's ID is placed into a trello board, and then if their name is there, it does nothing, whereas if it isn't, the place gets deleted (yes, a bit mean, but come on...). I have read the documentation, stating the table returns as JSON, but when I attempt to decode said JSON, I get the error.

23:44:52.722 - Unable to cast value to std::string
23:44:52.722 - Stack Begin
23:44:52.723 - Script 'Workspace.TrelloAPI.Script', Line 28
23:44:52.723 - Stack End

In the documentation

--GetCardInfo([Card ID],[Board ID]) returns an table 
--EX: {name="cardName",desc="cardDescription",...}

My script

local trello = require(script.Parent)

local boardID = trello:GetBoardID("AuthorisedPlaces")
local listID = trello:GetListID("PharmaMatic",boardID)
local cards = trello:GetCardsInList(listID)

print(game.CreatorId)

local alreadyPrinted = false

for a = 1,#cards do
	if tostring(cards[a]) == game.CreatorId then
		print'OK'
	else
		local cardId = trello:GetCardID("90119348",boardID)
		if not alreadyPrinted then
			print("Card id is "..cardId)
		end
		if cardId then
			local cardInfo = trello:GetCardInfo(cardId)
			if not alreadyPrinted then
				print("Card info: "..game.HttpService:JSONDecode(cardInfo))
			end
		end
		alreadyPrinted = true
	end
end

If anybody knows the reason why, I'd be grateful to hear. Thank you!

Uses NStrike's Trello API

function getAddon()
	if token~="" then
		addon="?key=aded73d328dce4a0698a6744856b3326&token="..token
	elseif getfenv(0).token~=nil then
		local val=getfenv(0).token
		addon="?key=aded73d328dce4a0698a6744856b3326&token="..val
	else
		error([[-Instructions
	 \n 1. Go to this link and click allow: https://trello.com/1/authorize?key=aded73d328dce4a0698a6744856b3326&name=Roblox+Api&expiration=never&response_type=token&scope=read,write	
	 \n 2. Copy the token in the page sent to you
	 \n 3. Paste the token in the Value of Token]])
	end
	return "&key=aded73d328dce4a0698a6744856b3326&token="..token
end
--Irrelevant Code Here

function T:GetCardID(name,boardid)
		local url
		if Private then
			getAddon()
			url="https://api.trello.com/1/boards/"..boardid.."/cards"..addon
		else
			 getAddon()
			 url="https://api.trello.com/1/boards/"..boardid.."/cards"..addon
		end
		local tab=HS:GetAsync(url,true)
		local tabl=HS:JSONDecode(tab)
		for k,ta in pairs(tabl) do
			for p,t in pairs(ta) do
				if p=="name" and t==name then
					return ta.id
				end
			end
		end
	end
	function T:GetCardInfo(cardid)
		--/1/boards/[board_id]/cards/[idCard]
		local url
		if Private then
			getAddon()
			url="https://api.trello.com/1/cards/"..cardid..""..addon
		else
		   	 getAddon()
			 url="https://api.trello.com/1/cards/"..cardid..""..addon
		end
		local re=HS:GetAsync(url,true)
		local tab=HS:JSONDecode(re)
		return tab
	end