Urgent: Change payment processor, add new React.js screens to Electron app, modify Nodejs AWS PostgreSQL back-end

I'm developer and I need your help with my project. The main problem is deadline, so it needs to be delivered very fast.
I need someone with knowledge of Node.js, Electron, React.js, PostgreSQL (Knex ORM is used). Bold plus would be knowledge of C# and AWS.
Candidate must have experience with credit card processors. Physical card terminal is used in this project.