My account does not display character and account details

My account is FlokkiVi#4370, and I am already level 21, but I cannot trade on the market or view character information on the website. When I try to send a private message on the market, I receive the following message: "Invalid query; Your account must be in-game to use this feature." If i in game i receive other message "Invalid query; Your account is unable to use this feature"

It seems like the website is unable to recognize my Steam account for some reason. Could you please advise what to do?