Tertiary education has dramatically changed after the outbreak of COVID-19. The use of the Learning Management System (LMS) in online learning has become popular. Many researchers are trying to investigate its features that influence the degree of acceptance and usage of learners among those techniques. However, some of their acceptance is not behavioral, but more on mental and abstract, which would be considered as engagement. In addition, academic disciplines would have a different focus on the integration of technology into their teaching and learning, thus, it would influence students\' acceptance of the technology. This research addressed this gap by studying university students in Hong Kong about the Technology Acceptance Model (TAM), and behavioral, agentic, cognitive, and emotional engagement. The findings extended the previous literature of TAM by adding engagement and academic discipline into the model. The current study demonstrates that LMS displays the potential of delivering learning and teaching materials amid the pandemic.