Roblox Webhooks Won't Display Discord Custom Emojis?

Trying to test discord webhooks for my game and everything works according to plan besides the fact that custom discord emojis will not display

the custom emoji name is :icemoji:

code:

local HS = game:GetService("HttpService")
local WebhookURL = "https://discord.com/api/webhooks/(mywebhookwillbehere)"

local MessageData = {
	["content"] = "bruh moment :icemoji:  ____ :sob:"
}
script.Parent.Touched:Connect(function(hit)
	if hit.Parent:FindFirstChild("Humanoid") then
		MessageData = HS:JSONEncode(MessageData)
	end
	HS:PostAsync(WebhookURL,MessageData)
end)

image link of my problem: https://gyazo.com/dd33974ce088d4b0db90fcc543650b3b