Context: The growing focus on ethics within SE, primarily due to the significant reliance of individuals' lives on software and the consequential social and ethical considerations that impact both people and society has brought focus on ethical software requirements identification and elicitation. User safety, privacy, and security concerns are of prime importance while developing software due to the widespread use of software across healthcare, education, and business domains. Thus, identifying and elicitating ethical software requirements from app user reviews, focusing on various aspects such as privacy, security, accountability, accessibility, transparency, fairness, safety, and social solidarity, are essential for developing trustworthy software solutions. Objective: This SLR aims to identify and analyze existing ethical requirements identification and elicitation techniques in the context of the formulated research questions. Method: We conducted an SLR based on Kitchenham et al's methodology. We identified and selected 47 primary articles for this study based on a predefined search protocol. Result: Ethical requirements gathering has recently driven drastic interest in the research community due to the rise of ML and AI-based approaches in decision-making within software applications. This SLR provides an overview of ethical requirements identification techniques and the implications of extracting and addressing them. This study also reports the data sources used for analyzing user reviews. Conclusion: This SLR provides an understanding of the ethical software requirements and underscores the importance of user reviews in developing trustworthy software. The findings can also help inform future research and guide software engineers or researchers in addressing software ethical requirements.