curl --request GET \
  --url https://discord.com/api/v10/users/{user_id} \
  --header 'Authorization: <api-key>'

{
  "id": "<string>",
  "username": "<string>",
  "avatar": "<string>",
  "discriminator": "<string>",
  "public_flags": 123,
  "flags": 0,
  "global_name": "<string>",
  "primary_guild": "<unknown>",
  "bot": true,
  "system": true,
  "banner": "<string>",
  "accent_color": 123,
  "avatar_decoration_data": "<unknown>",
  "collectibles": "<unknown>"
}