Answer Happy

Please assist me with pseudo code for an app.
App has 2 main users.
Both users register on the app.
user 1: registers with company details, name, contact number,
email address and uploads documents.This user is automatically
permitted to use the app.
user 2.
registers with company details, name, contact number, email
address and uploads documents.This user will rceeive an email
cofnriming whether or not they can use the app and sell items to
user 1 based on their documents they uploaded.
User 1 once loggd in can view a list of user 2's and once they
select a user 2 they can purchase items from them.
User 2 selected will receive confirmation of user 1's order and
accept the order.
once the order is accepted then the invoic will be generated and
sent to user 1 for payment.
tech sued will be Firebase and javascript for backend and
database.
Javascript and react for frontend.