View Source ExTDLib.Object.ChatEventMemberJoinedByRequest (ExTDLib v0.0.4)

A new member was accepted to the chat by an administrator.

NameTypeDescription
approver_user_idstringUser identifier of the chat administrator, approved user join request.
invite_linkchatInviteLinkInvite link used to join the chat; may be null.

More details on telegram's documentation.