Is there a better Software Architecture design for following requirements?

I am 2.5 years experienced software developer and doing kind of R & D related project. following requirements got from a client. So I came across an architecture diagram and functional flow diagram. with my experience and all other things, I'm so confused at some points.

Here are the requirements -

1. Data exchange platform for companies to exchange their data securely.

2. Each company will have its own user account where it will log in for uploading and receiving data.

3. Cloud storage will be set up at the back end where the data will be stored. Data will be stored in XML format.

4. When a company requests data if that request is accepted by the asked company then that data will be shared through the Spring Data flow pipeline.

5. We need a web portal for the front end and a cloud at the back end to support this exchange.

Mandatory Tech Stack,

• Spring boot
• Spring Data flow
• Cloud static storage
• React front end.
• Any other tech thing I am free to add.

I m attaching Diagrams here.

Flow Diagram.

Architecture Diagram.

Can anyone please review it and add comments?