Humankind an Amplifiers are not connection and service is not avaiblie

I don't know if I understood your question correctly, but if the objective is to find out how to use the avatar created in Humankind in your Amplifiers profile, know that it is not possible. But if the objective is to synchronize to release badges etc, within the profile page there is a link to synchronize (Steam, Epic or Twitch), by doing this it is possible to share your persona (Humankind's avatar) with other players and download from others.