Hello Daniel, I hope you are doing well and thanks for your interest in our courses. According to our records, you bought “Android Apps for Arduino with MIT App Inventor 2”. If you go to this tab, you can scroll down and open the course: https://rntlab.com/courses/
Or use this direct link: https://rntlab.com/welcome-to-android-apps-for-arduino-with-mit-app-inventor-2/
Then, you can download the course eBook in PDF format.
Thanks for your interest and let me know if you need further help.