View Source ExTDLib.Method.BanChatMember (ExTDLib v0.0.4)

Bans a member in a chat. Members can't be banned in private or secret chats. In supergroups and channels, the user will not be able to return to the group on their own using invite links, etc., unless unbanned first. Returns object_ptr<Ok>.

NameTypeDescription
chat_idstringChat identifier.
member_idMessageSenderMember identifier.
banned_until_datenumberPoint in time (Unix timestamp) when the user will be unbanned; 0 if never. If the user is banned for more than 366 days or for less than 30 seconds from the current time, the user is considered to be banned forever. Ignored in basic groups and if a chat is banned.
revoke_messagesboolPass true to delete all messages in the chat for the user that is being removed. Always true for supergroups and channels.

More details on telegram's documentation.