Provided are a method for a first device to perform wireless communication, and a device supporting same. The method may include the steps of: receiving first downlink control information (DCI), including information related to a first physical uplink control channel (PUCCH) resource and information related to sidelink (SL) resource allocation, from a base station through a first physical downlink control channel (PDCCH); transmitting a physical sidelink control channel (PSCCH) and a physical sidelink shared channel (PSSCH) to a second device on the basis of the information related to the SL resource allocation; receiving SL hybrid automatic repeat request (HARQ) feedback from the second device through a physical sidelink feedback channel (PSFCH) related to the PSSCH; receiving second DCI, including information related a second PUCCH resource and information related to downlink (DL) resource allocation, from the base station through a second PDCCH; receiving a physical downlink shared channel (PDSCH) related to the second PDCCH from the base station on the basis of information related to the DL resource allocation; and transmitting, on at least one of the first PUCCH resource or the second PUCCH resource, at least one of the SL HARQ feedback or HARQ feedback related to the PDSCH to the base station. Here, the first PUCCH resource and the second PUCCH resource may overlap in the time domain.