We have an app where we integrate with lots of third part POS. we aggregate the POS data after the user integrates their POS. we currently use custom aggregator (ELT) to collect this data periodically once the integration is completed.
We do use a third party system to store this. however, we want to move to our own system. I am planning this move using a microservice that can store credentials and rotate the access token.
is this an appropriate system design?
The idea is that the once the user initially integrates we will store them on the main app as well as store the credentials in a RabbitMQ. The microservice will then fetch the data from RabbitMQ and then set it up.

Is there something that I am missing? Is this good enough?

havent tried anything. just a system design question