ERP Integration API

Logitax is a tax technology platform focused on India. Logitax platform is intending to build an open API architure for small and large data files communication.
What is required:
1. Implement the O-auth for API authentication
2. Impelemnt the POST API with Sync and Async Response
3. Implement the GET API for all Async and other use cases

Expectations:
Prior experience in -
1. O-auth designing and implementation
2. Designing open API architecture for application integrations
3. Dot Net Core + MS SQL
4. Micro services

Data types for integration:
CSV/ JSON/ Excel

APIs designs - 3
API endpoints - around 10