android mobile app (react native or flutter) with firebase database

We want a app with admin app from admin app we can see all the active users and the users who has purchased the course The course will be as pdf files so we'll disable screenshot, screenrecording and copying From admin app admin will create class subject and upload pdf From user app one can register themself using email verification and then they will see all the course available and demo pdf will be there and they can purchase it and can see the pdf in app can't download from admin we can send notification to all users payment metiod will be card and UPI phonepe googlepay etc in admin app we can see how much revenue has been generated monthly and total App will have dark mode also We wanna use firebase for backend these are the main features budget is fixed and timeline is 10 - 12 days