Embodiments of the present disclosure relate to transmission of sidelink feedback information on unlicensed spectrum. The first device transmits a configuration to a second device and a third device. The configuration indicates a primary resource and at least one backup resource, where the primary resource is to be used by the third device for transmitting feedback information of a sidelink transmission to the second device, the sidelink transmission being transmitted by the second device on an unlicensed resource, and the at least one backup resource is to be used by the third device for transmitting the feedback information of the sidelink transmission without performing a channel assessment.