Proposed is an operation method of a first device in a wireless communication system. The method may comprise the steps of: receiving, from a base station, TDD-UL-DL configuration information including information related to a first slot pattern and information related to a second slot pattern; acquiring the number of first SL slots related to the first slot pattern and the number of second SL slots related to the second slot pattern on the basis of first SCS related to SL communication and the TDD-UL-DL configuration information; and transmitting, to a second device, a PSBCH including information related to the number of the first SL slots and information related to the number of the second SL slots.