I’ve also created a guide for this: Guide - How to Use the ZS06 or UFO-R11 Zigbee IR controllers with SmartIR
Note that there’s no need to add “ir_code_to_send” before every command.
You can include it directly in the controller_data field like this:
zigbee2mqtt/FRIENDLY_NAME/set/ir_code_to_send
This way, you can use the converted code file directly without editing it.