Facebook is not required to take the Painterly Landscape Course.
All course content and live session recordings will be available on the course website, which you'll have lifetime access to. You can complete the entire course successfully without Facebook.
Facebook is an optional bonus that helps you connect with other students, share your artwork, and receive feedback from Alain, Community Mentors, and fellow artists. The community is incredibly supportive and encouraging, but it's entirely up to you whether to participate.