This research examines the factors influencing the ethical use of LLM chatbots in higher education. Environmental, personal, and perceived risk factors contribute to the ethical use of AI chatbots. Personal factors mediate the relationship between environmental influences and ethical use. fsQCA highlights the ineffectiveness of deterrent strategies in addressing AI plagiarism in the era of LLM chatbots. fsQCA further shows that ethical climate alone is insufficient and must be complemented by supervision and personal factors.