QwertyBoos

Hello guys i began to create a programm and i want to send messages any friend through api. I found https://api.steampowered.com/ISteamWebUserPresenceOAuth/Logon/v0001 and pass access_token - https://steamcommunity.com/dev/managegameservers and dev api key and i get an answer UnauthorizedAccess is denied. Retrying will not help. Please verify yourkey=parameter. What is that problem? How i can fix that? Help pls!