OptionalmetadataObject mapping application role connection metadata keys to their string-ified value (max 100 characters) for the user on the platform a bot has connected
Optionalplatform_The vanity name of the platform a bot has connected (max 50 characters)
Optionalplatform_The username on the platform a bot has connected (max 100 characters)
See
https://discord.com/developers/docs/resources/user#update-user-application-role-connection