An embodiment relates to a method for operating a transmitting user equipment (TX UE) in a wireless communication system, the method including: a step in which the TX UE requests a base station for a sidelink resource through a first beam; and a step in which the TX UE triggers first buffer status reporting (BSR), wherein the TX UE cancels the first BSR on the basis of a beam failure recovery (BFR) trigger pertaining to the first beam.