Anahita:
The 2021 exam is still based on PMBOK 6, so all of processes and knowledge groups will be the same. While PMI has stated that there will be more Agile-related questions on the 2021 exam, I have not seen too many reviews on the Forum boards with respect tot he next exam and new format.
Take a look at PMI's information on the new exam format. It looks like the text is much more interactive now, with questions like arranging processes, multiple answers and the old-style pick the right answer.
Good luck.
Harry