Create response message
The Create response message block is used to respond to a command or component interaction. Usually each command or component interaction must create a message response. The only exception is when you show a modal instead.
You can either configure the message in the block directly or use a message template instead. In both cases you can add embeds, components v2 layouts, and interactive components to the message. The only case where it's better to use a message template is when you want to use the same response in multiple places.
If the message contains interactive components, the flow will be suspended until the user interacts with the message. See Sub-Flows for more information on how interactive components work.
In the blocks attached to a button or select menu, user is whoever clicked it. Use origin.user for the person who ran the command. See Who is user in a sub-flow?.