Please refer to About the Scripting Support category. Your current question is phrased up to be asking for code, which is not proper use of this category. There are also no indications that you have attempted this problem or searched for solutions.
When working with HttpService to fetch responses from web servers, you are going to be using a GET request in any medium, whether it’s GetAsync or RequestAsync with the GET method passed to it.
local returnedData = HttpService:GetAsync("yourURL")
Once you have that in, you’re done from Roblox’s side. GetAsync is a callback, so now you need to focus on the web server returning a response to a GET request. I personally don’t know how to do this so that’s up to you to figure out or for someone else to reply with.
@Operatik JSON Encode and Decode are only for responses returned in JSON.