As a crucial factor in the success of software startups, the role of the Product Manager (PM) is often overlooked, despite the high failure rate (63%). To bridge this gap, a Structured literature Review (SLR) is getting conducted. Following a rigorous study selection strategy, 134 studies have been selected, of which 79 directly linked to the Requirements Engineering (RE) domain. By focusing on the RE studies, and applying ChatGPT, 343 unique PM tasks, spanning 98 activities have been identified. Out of these studies, only 7 (8,86%) consider explicitly both a startup context and the role of the PM. This study aims to contribute to the field by providing valuable input to develop a novel, startup -specific framework that helps to refocus the PM to those activities that are expected will capture most of the expected value. The future framework aims to enhance early-stage product decision-making for founders, increasing their probability of success. It not only has practical implications for software startups, but could also spur further collaborative academic RE research. Furthermore, the study could serve as a valuable resource for researchers and practitioners in the domain of RE and startups.