reopen
Use this method to reopen a closed topic in a forum supergroup chat. The bot must be an administrator in the chat for this to work and must have the can_manage_topics administrator rights, unless it is the creator of the topic. Returns True on success.
Parameters
chat
Unique identifier for the target chat or username of the target supergroup (in the format @supergroupusername)
message
Unique identifier for the target message thread of the forum topic