A method for performing wireless communication by a first device includes: receiving information related to a time division duplex (TDD) slot configuration, transmitting, to a second device, a sidelink-synchronization signal block (S-SSB), the S-SSB including a sidelink primary synchronization signal, a sidelink secondary synchronization signal, and a physical sidelink broadcast channel, and transmitting, to the second device, a physical sidelink shared channel based on the information related to the TDD slot configuration. Candidate resources to which a bitmap related to a sidelink resource pool is applied (i) are configured based on the information related to the TDD slot configuration and (ii) include one or more slots. Configuration information related to a sidelink symbol included in each of the one or more slots is received, the configuration information including information related to a position of the sidelink symbol configured to be the same for the candidate resources.