setMessageReaction

Use this method to change the chosen reactions on a message
Service messages of some types can't be reacted to
Automatically forwarded messages from a channel to its discussion group have the same available reactions as messages in the channel
Bots can't use paid reactions

Parameters for set-message-reaction
Field Description
chat_id * Unique identifier for the target chat or username of the target channel (in the format @channelusername)
message_id * Identifier of the target message
If the message belongs to a media group, the reaction is set to the first non-deleted message in the group instead.
reaction A JSON-serialized list of reaction types to set on the message
Currently, as non-premium users, bots can set up to one reaction per message
A custom emoji reaction can be used if it is either already present on the message or explicitly allowed by chat administrators
Paid reactions can't be used by bots.
is_big Pass True to set the reaction with a big animation