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

Creates a video chat (a group call bound to a chat). Available only for basic groups, supergroups and channels; requires can_manage_video_chats rights. Returns object_ptr<GroupCallId>.

NameTypeDescription
chat_idstringIdentifier of a chat in which the video chat will be created.
titlestringGroup call title; if empty, chat title will be used.
start_datenumberPoint in time (Unix timestamp) when the group call is supposed to be started by an administrator; 0 to start the video chat immediately. The date must be at least 10 seconds and at most 8 days in the future.
is_rtmp_streamboolPass true to create an RTMP stream instead of an ordinary video chat; requires creator privileges.

More details on telegram's documentation.