Students will need to complete exam setup ahead of each exam day on the specific computer that they plan to use for testing. Exam setup will be available 3 days before exam day and must be completed no later than the day before exam day.

Students must understand that testing starts at exactly 12 p.m. Eastern Daylight Time and 4 p.m. Eastern Daylight Time. Digital exams for a specific subject start at the exact same time, worldwide.  Students will need to check in online 30 minutes before the official start time.

Beginning in April, students and educators can access the exam application and a digital exam practice resource that enables students to confirm the viability of their technology well before test day, experience the exam day flow, and practice answering exam questions, including each type of multiple-choice and free-response question they’ll encounter on exam day.

https://apcentral.collegeboard.org/about-ap-2021/updates/four-steps-before-digital-test